TX PACT science 4-8: Domain I & II- Scientific Instruction & Scientific process

A student wants to determine how the brightness of two bulbs vary with applied voltage. The student sets up a circuit with a variable voltage source and a bulb, and measures the bulb brightness with a meter. The results are shown in the table. Which data show the strongest evidence that brightness does NOT increase linearly with voltage?

Data for the LED bulb. The LED data show a strong nonlinear relationship because the LED is off until a threshold voltage is reached, and then the LED has a relatively constant brightness at all voltages. see screenshot

Converting Units - Dimensional Analysis

Dimensional analysis (or unit analysis) is the process of converting within or between systems by multiplying by unit fractions. Since the items on top equal the items on bottom (ex: 12 inches = 1 foot), each of these fractions are actually equal to one.

Studying every scientist who has made a significant contribution to our scientific knowledge would be very difficult and time-consuming. It is important to understand that our knowledge comes from many scientists, of both genders and diverse backgrounds, all working towards a deeper understanding of the way the universe works.

Diversity in Science It is important for students to understand that scientists come from diverse backgrounds, and our knowledge of the universe is thanks to the perspectives of many different scientists with a variety of previous experience and background knowledge. These scientists contributed to our understanding of the world despite whether they were rich or poor, male or female, educated or not, rural or urban, and regardless of which language they spoke or whether they even had a personal history of scientific investigation. For example, Marie Curie was a Polish woman, Leonardo da Vinci was a gifted artist, and Michael Faraday was a bookbinder's apprentice. Teachers must encourage students in their scientific endeavors and show them that diverse backgrounds are a valuable tool in the advancement of scientific discovery.

measurement

a number that shows the size or amount of something

Mr. Orlando is on the far side of the room when he sees a student mishandling equipment during a laboratory activity. Which of the following is the best first step Mr. Orlando should take to resolve the problem?

Using proximity, or moving close to a misbehaving student, is an excellent first step. It does not escalate the issue, but lets the student know you see what he or she is doing and that it is inappropriate. Often the student will then self-monitor. The next steps might involve quietly correcting the student and talking with the student individually during recess.

Which of the following instruments would be most useful to find the volume of a very large textbook?

Volume is found by multiplying the height, width, and length of an object. To best find these measurements of a large textbook, a metric ruler would be most appropriate.

Waft

Wave the air toward the face. The safe way to smell a test tube.

Francois Jacob and Jacques Monod

Contributed greatly to the field of lysogeny and bacterial reproduction by conjugation Both won Nobel Prize

Scientific behavior- 240

Converting Units - Proportional Reasoning

Students do an experiment in biology class to study the effects of organic fertilizer on growth and production of tomato plants. They choose two tomato plants of the same variety and size, which are planted in identical pots using the same soil and placed next to each other near a window. Plant A is fertilized twice throughout the experiment while Plant B is not fertilized. Students measure the amount of fruit produced and the height of the plants. Which of the following is the independent variable?

Fertilizer is the independent variable because it is the only variable that was manipulated.

Common safety equipment to have in a classroom:

First aid kit - treat minor injuries Fire extinguisher - put out flames on materials Fire blanket - put out flames on a person Goggles - protect eyes when using glassware or chemicals Fume hood - pulls chemical gasses up and away from people Body shower / Safety shower - wash chemical spills off a person Eyewash station - wash chemicals out of a person's eye

Which of the following is a safe laboratory procedure?

Fume hoods are designed to increase airflow to remove fumes and protect any lab occupant from inhaling them. Volatile compounds are those that have a high vapor pressure at room temperature, which leads to their evaporation or sublimation into the gas phase. Many volatile compounds are quite toxic and can produce long-lasting health effects.

drawing a conclusion

after recording data, compare the data with that of other groups. A conclusion is the judgement derived from the data results.

systematic and random error

all experimental uncertainty is due to either random errors or systematic errors

Bar Graph (Histogram)

compares the amount of something. Bar graphs are used for categories and histograms for numeric ranges.

Mathematical Models

models that use mathematical formulas, variables, and language to refer to relationships and processes in a system the formula for gravitational force, F=mg

Which of the following can lessen the impact human population growth has on the environment?

technology Technology can help mitigate some of the impacts of humans.

Tolerance (in stats)

the amount of measurement error that is allowed

Grams (g)

the base metric unit of mass

Liters (l)

the base metric unit of volume

skill 2.2

the concepts of precision, accuracy, and error with regard to reading and recording numerical data from a scientific instrument

Meniscus

the downward curve on the surface of a liquid caused by the adhesion of the liquid on the glassware

What must a scientist consider when deciding which tools to use to gather data?

the expected outcome of the investigation The expected outcome of the investigation is the most important factor when determining which tools to use to gather data.

tare

to set a balance equal to zero to ensure an accurate measurement with no contaminants

the scanning electron microscope (sem) .

was developed in the 1950s. Instead of light, a beam of electrons passes through the specimen. scanning electron microscopes have a resolution about one thousand times greater than light microscopes. the disadvantage of the SEM is that the chemical and physical methods used to prepare the sample resulted in the death of the specimen.

Example 2 (English to metric): If 1 cup (c) is about 0.24 liters (l), how many liters is 15 cups?

1. Draw two fraction lines equal to each other and include units. c/1=c/1 2. In the first fraction, write the provided conversion. In this case, the conversion of cups to liters was provided. 1c/0.241 = c/1 3. n the second fraction, write the known amount. Place x for the unknown amount. In this case, start with 15 cups and solve for liters. 1c/0.241 = 15c/x variable (1) 4. Cross multiply and divide to solve for x. 1 c×x l=15 c×0.24 l x1= 15c x 0.241 /1c x=3.61 5. Check that the answer is reasonable. Since there are about 4 cups in a liter, it makes sense that 15 cups would be less than 4 liters. Convert any unit to a different unit using a pair of equal fractions. Make sure that the same unit is in both numerators and the other unit is in both denominators.

Steps to convert using proportional reasoning:

1. Draw two fraction lines equal to each other. Write the units in all four places. One unit should be in both numerators and the other unit in both denominators. 2.In the first fraction, write the values from the provided conversion next to the corresponding units. 3. In the second fraction, write the known amount beside its unit. Place x for the unknown amount. 4. Cross multiply and divide to solve for x. Check that the answer is reasonable.

Although it does not matter which unit is in the numerator and which is in the denominator, it is critical that the same unit is in both numerators and the other unit is in both denominators. The conversion rate also must be represented as one fraction. If either of these is wrong, you will still be able to solve for x, but it won't be the correct amount.

1. Example 1 (metric to metric): Convert 7,250 meters to kilometers. Draw two fraction lines equal to each other and include units. m/km = m/km 2. in the first fraction, write the provided conversion. In this case, meters to kilometers is a known conversion factor from the metric system. There are 1,000 meters in 1 kilometer. 1000m/1 km = m/km 3. in the second fraction, write the known amount. Place x for the unknown amount. In this case, start with 7250 meters and solve for kilometers. 1000m/1 km = 7250/x variable km 4. Cross multiply and divide to solve for x. x km * 1000m =7250 m x 1 km x km = 7250 m X 1 km/ divided by 1000m x= 7.25 km 5. Check that the answer is reasonable. It makes sense that there would be 7.25 km in 7,250 meters since each 1 km is the same as 1,000 m.

The following are some of the guiding principles of scientific ethics:

1. Scientific honesty: not to fraud, fabricate, or misinterpret data for personal gain 2.caution: to avoid errors and sloppiness in all scientific experimentation 3. credit: give credit where credit is due and not to copy 4. responsibility: only to report reliable information to the public and not to mislead in the name of science. 5. freedom freedom to criticize old ideas, question new research and freedom to research to research. many more principles could be added to this list. Though these principles seem straightforward and clear, it is very difficult to put them into practice since they could be interpreted in more ways than one. Nevertheless, it is not an excuse for scientists to overlook these guiding principles.

Labeling Samples It is best practice to label all chemicals as follows:

1. The compound name, written out in words 2. Who made the sample 3. The date the sample was made Hazards associated with the material

The scientific method is used to guide scientists through the steps of planning the process and conducting the experiment. These steps include:

1. The scientist identifies the problem and attempts to explain it. 2. The scientist makes observations, recording information gathered using the five senses. 3. The scientist forms a hypothesis, or prediction, based on the observations. 4. The scientist tests the hypothesis in an experiment. In an experiment, a scientist may have a control group, or group which does not receive the experimental treatment, and an experimental group, which does. 5. The scientist records and communicates data, or measurements and observations taken during the experiment. 6. The scientist draws a conclusion stating whether the hypothesis was supported or rejected. 7. The scientist reforms the hypothesis and designs a new experiment. Students should understand that following the scientific method often results in a "feedback loop", where the results lead to more possible hypotheses and continued testing.

Proportional reasoning can also be used to solve word problems. Example 3 (word problem): Jessica is washing cars for a local fundraiser. She knows that it takes 2 bottles of wash for 9 cars. If they want to wash at least 55 cars for the fundraiser, how many bottles should she buy?

1. draw two fraction lines equal to each other and include units. bottles/cars = bottles/cars 2. in the first fraction, write the provided conversion. In this case, the ratio of bottles of wash to number of cars was provided. 2 bottles/9 cars = bottles/cars 3. In the second fraction, write the known amount. Place x for the unknown amount. In this case, start with 55 cars and solve for bottles. 2 bottles/9 cars = x bottles/ 55 cars 4. Cross multiply and divide to solve for x. 9 cars * x bottles= 2 bottles * 55 cars x bottles= 2 bottles X 55 cars/ 9 cars x=12.22 bottles Since bottles must be bought in whole units, Jessica needs 13 bottles . 5.Check that the answer is reasonable. Since there are about 2 bottles for every 10 cars, it makes sense that it would take about 13 bottles for 55 cars.

Use the following conversion factors to answer the question below. 1 Pa = 0.00750062 mmHg (at 0°C) 1 atm = 1.01375 x 105 Pa During an experiment, a student measures and records a pressure of 1.20 x 105 Pa. What is this pressure in atmospheres and millimeters of mercury at 0°C?

1.18 atm and 900 mmHg Set up a ratio to convert units from Pa to atm and another ratio to convert from Pa to mmHg. 1.20 \times 10^{5}Pa⋅\frac{1 atm}{1.01375 \times 10^{5}Pa}=1.18 atm1.20×105Pa⋅1.01375×105Pa1atm​=1.18atm 1.20 \times 10^{5}Pa⋅\frac{7.50062 \times 10^{-3} mmHg}{1 Pa}=900 mmHg1.20×105Pa⋅1Pa7.50062×10−3mmHg​=900mmHg see screenshot

deci

1/10 the base unit

centi

1/100 the base unit

milli

1/1000 base unit

kilo

1000x the base unit

hecta

100x the base unit

Of the following, which is most likely the distance from a classroom on the second floor to the playground outside at the end of the wing?

105 meters This is a reasonable distance as it is about the length of a football field.

Joseph owns a distributing company that repackages cornmeal from bulk quantities into smaller packages. If Joseph wants to fill 100,000 bags that each hold 10 grams of cornmeal, how many kilograms of cornmeal should he buy?

10^3 Multiply the quantities \frac{10 \text{ g}}{\text{bag}}bag10 g​ and 100,000 bags, and convert grams to kilograms. The arithmetic can be simplified by using powers of 10 as follows: 10 g = 101 g 100,000 bags = 105 bags 1000 g = 103 g = 1 kg Therefore: \frac{10^{1} \text{ g}}{\text{ bag}} \times 10^{5} \text{ bags} \times \frac{1 \text{ kg}}{10^{3} \text{ g}}=10^{3} \text{ kg} bag101 g​ ×105 bags ×103 g1 kg​=103 kg. see screenshot

deca

10x the base unit

A pool empties at a rate of 12 quarts every 2 minutes. How many hours and minutes will it take to completely empty the pool which contains 12,000 gallons? (1 gallon = 4 quarts)

133 hours and 20 minutes Both quarts and minutes needs to be converted. 12 quarts = 3 gallons. 12,000/3 = 4,000 x 2 minutes = 8,000 minutes/60 minutes = 133 hours and 20 minutes

James Watson and Francis Crick

1953. Built first accepted DNA model explaining specific structure and properties of DNA.- discovered that the DNA molecule is a double helix. This structure made it possible to explain DNA's ability to replicate and to control the synthesis of proteins.

Which of the following is the same as 1 \times 10^{3}1×10^3 meter?

1kilometer = 1000 meter = 1 \times 10^{3}1×10^3 meter

Scientific Process: unifying framework

240 module

According to the table, how many milliliters are in 1 gallon?

3,788.8 mL A conversion with ounces as a middle point can be set-up. \frac{16 \text{ c}}{1 g} \times \frac{8 \text{ oz}}{1 \text{ c}} \times \frac{29 \frac{3}{5} \text{ mL}}{1 \text{ oz}} = 3,788.8 \text{ mL}1g16 c​×1 c8 oz​ ×1 oz29 53​ mL​=3,788.8 mL see screenshot

Which of the following is equivalent to 305 L?

3.05 × 10^5 mL Scientific notation is used to express magnitude. There are 1000 mL (or 1 × 10^3 mL) in 1 L. Multiply 305 L by 1000 gives 3.05 × 10^5 mL.

Which of the following is equivalent to 3 meters?

300 centimeters 1 meter is equal to 100 centimeters. "Centi" sounds like "century" which has 100 years.

If 2.54 cm = 1 in, about how many inches are in 1 meter?

39.4 in There are 100 cm in 1 m, so 100cm/m ÷ 2.54 cm/in ≈ 39.4 inches/m.

A doctor prescribed a 250 mg capsule of a common antibiotic for strep throat. The pharmacist had only 1 gram of the antibiotic in stock. How many capsules of medicine can the patient get from the pharmacist?

4 The pharmacist has 1000 mg (since 1 gram = 1000 milligrams). Since each capsule needs 250 mg, proportional reasoning can be used. \frac{1 \text{ cap}}{250 \text{ mg}} = \frac{x \text{ cap}}{1000 \text{ mg}}250 mg1 cap​=1000 mgx cap​ see screenshot

If 2.2 lb = 1 kg, and Mary weighs 120 lbs, how much does she weigh in kg?

54.545 g round to 55 kg

Susan travels at a rate of 60 miles per hour for 3 hours. Her car uses on average one gallon of gas per 30 miles. How many gallons of gas does she use on her trip?

6 The two unit rates: (30 miles per 1 gallon) and (60 miles per hour) can be used to convert from 3 hours to gallons of gas. Susan travels 180 miles (60 miles/hour × 3 hours). 180 miles/(30 miles/gallon) = 6 gallons of gas.

Avogadro's number equals approximately 6.022 x 1023 and is the number of atoms in 1 mole of a substance. If there are 10 moles, how many atoms are in the substance?

6.022 x 10^24 Multiplying Avogadro's number by 10 moves the decimal one place value to the right or increases the exponent by one.

Salome's mousetrap car completed a 30-meter stretch of track in 17 seconds. Which of the following is closest to the speed of the car in kilometers per hour?

6.3 kilometers per hour Calculate the car's speed in meters per second by dividing distance by time: v=\frac{30 m}{17 s}=1.8 \frac{m}{s}v=17s30m​=1.8sm​. Convert to kilometers per hour using the conversion factors 1000 m = 1 km and 3600 s = 1 hr: 1.8 \frac{m}{s}⋅\frac{1 km}{1000 m}⋅\frac{3600 s}{1 hr}=6.3 \frac{km}{hr}1.8sm​⋅1000m1km​⋅1hr3600s​=6.3hrkm​.

If sound can travel at approximately 0.21313 miles per second, how many miles could sound travel in 1 year?

6.7×10^6 To convert miles per second to miles per year, multiply the value by several rate factors: 0.21313 miles/sec \times 60 sec/min \times 60 min/hr \times 24hr/day \times 365 days/yr = 6.7 \times 10^{6} miles/yr0.21313miles/sec×60sec/min×60min/hr×24hr/day×365days/yr=6.7×106miles/yr. see screen shot

Ms. Sanchez orders 221 feet 8 inches of string to cut and use for manipulatives in her math class. How much string will each student receive if she cuts the entire length into 28 equal pieces?

7 ft and 11 in Convert the total string length into inches: (221 × 12) + 8 = 2660 inches. Divide by 28 to get the length per student: 2660/28 = 95 inches/student. Convert to feet and inches: 95/12 = 7 remainder 11. Each student gets 7 feet 11 inches.

How many feet are in 27 km?

9,100 ft (5280 ft / 1 mile) × (1 mile / 1.6 km) × (27 km / 1) = 89,100 ft.

lab report

A good way to communicate the results of an experiment to others.

When determining the accurate measurement of a liquid, which piece of laboratory equipment would be best to find the liquid's volume to the nearest milliliter?

A graduated cylinder has graduated milliliter measurement lines to measure volume.

Which of the following accurately summarizes the difference between a hypothesis, a scientific theory, and a scientific law?

A hypothesis is a predicted outcome, a theory is a proposed explanation based on evidence, and a law is a documented description of observations surrounding a phenomenon.

Hypothesis vs Theory vs Law

A hypothesis is a statement that can be tested. A theory is a general principle or body of principles that has been developed to explain a wide variety of phenomena. A law is a mathematical relationship that is consistently found to be true. A common misconception among students is the distinction between a hypothesis, theory, and scientific law. A hypothesis is a testable prediction based on observations. A theory is a proposed explanation based on evidence which may or may not be testable. It unifies hypotheses and provides a general explanation for phenomena. A scientific law is a proven and documented description of observations surrounding a phenomenon.

Measurement Principles

A measurement is a number that shows the size or amount of something. Because of the limitations of human (and machine) error in using measurement tools, measurement is never exact; it is always an approximation.

Proportion

A statement that two ratios are equivalent. 2/3 = 4/6

Equilibrium (of a System)

A system in balance; no forces acting on objects within the system A pendulum has stopped and hangs downward.

Hypothesis

A testable prediction, often implied by a theory- an educated guess or what is expected of the experiment. the entire experiment should relate to this problem.

Which of the following is an example of a model?

A=εbc. Scientific models represent phenomena, objects, and physical processes consistently and logically. The equation A=εbc is an example of a model.

Shirley is peer-reviewing her classmate's lab report. She notices that their data is presented in several data tables and then described. What suggestion should she make to best help her classmate improve this report?

Add graphs of the data to show trends and relationships. Using graphs and charts to show trends and relationships helps the reader better analyze the data.

Of the following, which is most appropriate to do after testing a hypothesis?

After testing a hypothesis it is best to organize the data so that conclusions can be drawn.

Decision Making and Science

Although scientists work to improve society, technology, and our overall quality of life, some advancements require careful planning and analysis before they are implemented. Ethical standards, economics, and personal and societal needs drive decisions about the use of science. It is important for scientists to estimate the possible impact of certain changes before they are put into place. Students should recognize that alternative energy sources, hybrid automobiles, cloning, stem cell research, genetic testing, and research on animals for medical advancement are a few problems identified where a risk assessment is needed for scientific breakthroughs. The process of risk assessment leads scientists to identify problems, predict an outcome, conduct the research, interpret the results, and then make decisions, balancing scientific and economic outcomes.

Which of the following is an example of risk assessment for societal advancement in science?

An agent of the Environmental Protection Agency performs an Environmental Impact Assessment prior to the construction of a new bridge. An Environmental Impact Assessment is a form of risk assessment that weighs the risks to the environment against the societal and economic gain to be achieved by the new construction.

Experimental Investigations - Identifying Variables

An experiment on bean plants was set up to test plant growth in response to the type of fertilizer. What would the different variables be classified as? The type of fertilizer is the independent variable causing the change in plant growth. The amount of plant growth would be the dependent variable because it depends on the type of fertilizer used. The amount of water, sunlight, and any other growing conditions would be controlled variables. They must be constant in order to attribute changes in growth solely to the fertilizer.

Repeatability

An important step in the scientific method is the communication of results. During peer review, other members of the scientific community read and fact-check the papers. During this and after publication, scientists may repeat the experiment and ensure the results are able to be replicated. The more replication happens, the more reliable the results are. When an investigation is not easily repeated, it is important to consider why. Factors influencing the outcome of the experiment may cause skewed or corrupted results. For example, laboratory equipment may not have been calibrated correctly in the original experiment. Having peers attempt to repeat investigations allows scientists to ensure that they are reporting valid and reliable data. As scientists are able to repeat one another's experiments and achieve the same results, the results are considered to be proven. This solidifies scientific laws. The more the experiments are repeated and verified, the more validity the scientific law has. On the other hand, sometimes new evidence is possible (often from new technology). Scientific theories and knowledge are not static. They are always subject to revision in light of new evidence. In the school laboratory, repeatability can be stressed by having multiple trials for experiments and by comparing data across groups of students.

Which statement explains a direct correlation between form and function in the structure of the circulatory system?

Arteries spread into tiny capillaries, increasing the surface area for gas exchange. Because the parts of a system have a distinct function, their form and function must have a direct correlation. The only answer choice that correlates form and function focuses on surface area of capillaries for gas exchange.

Types of Power Sources

As society becomes more and more dependent upon technology, it is important to consider what resources we will use to power our homes and devices. In order to maintain a sustainable supply of power, we must use renewable resources when possible. These resources can be replenished at the same rate or faster than the rate at which they are used. Nonrenewable resources, on the other hand, will be depleted before more can be made. The table below lists examples of renewable and nonrenewable resources, as well as pros and cons of each: see screen shot

How might scientific research be advanced in a society?

Assessing needs and using scientific research to address those needs in order to benefit society and our environment. This is the most responsible and ethical way of advancing scientific research.

Daily pollution reports imply that ozone is a pollutant, yet lack of ozone seems to create an undesirable ozone hole. Which of the following best explains this apparent contradiction?

At ground level, ozone is a pollutant that can harm living things; in the upper atmosphere ozone blocks harmful radiation. Ground level ozone is a harmful pollutant; however, ozone located in the upper atmosphere blocks the Earth from much harmful ultraviolet radiation. Chlorofluorocarbons and similar compounds act as catalysts that break down atmospheric ozone, especially over the poles, and create an ozone hole.

The Greenhouse Effect

Carbon dioxide, methane, and water all act as greenhouse gases that heat the earth. When heat that is radiated toward space from the earth is absorbed by a greenhouse gas, the gas re-radiates the heat in all directions. Instead of escaping into space, some of that heat travels toward the earth and warms it further. This process is called the greenhouse effect.

Which of the following statements about chimpanzees most effectively relates structure to function?

Chimpanzees have opposable thumbs on all four hands to swing from trees. This connects the form of chimpanzees, having thumbs on all four hands, to function, which they use the thumbs to help them hold onto tree branches.

Activities For Critical Thinking

Connecting content to real-world situations will help students understand how knowledge of science concepts makes decisions about life easier. For example, teaching a student to understand and use simple machines could decrease the amount of work exerted while helping his neighbor move heavy boxes. Understanding weather patterns can help students make informed decisions about appropriate clothing for certain atmospheric conditions or locales. Teachers need to identify environmental problems and explain their impact on the environment. Some examples include a polluted water source, finding a home for a pet, dealing with a lack of water in a habitat, and understanding the importance of the conservation of resources. It is important for students to be able to employ critical-thinking skills and logical reasoning to provide a solution to the problem based on the evidence.

Which type of investigation has two manipulated variables and investigates possible relationships between the variables?

Correlational research Correlational research looks for patterns or relationships between two variables. A researcher studying diet and rates of heart disease would be an example of this type of research.

Meredith wants to know if there is a relationship between grade-point average and involvement in extracurricular activities. She gives a group of students two surveys: one about their involvement in extracurricular activities and one about their grades. What type of research is this?

Correlational research involves studying two variables without controlling other aspects of the study.

Right to know law

Covers science teachers who work with potentially hazardous chemicals and the law requires that employees be informed of potentially toxic chemicals. An inventory must be made available if requested. The inventory must contain information about the hazards and properties of the chemicals. Training must be provided in the safe handling and interpretation of the material safety data sheet.

The Ozone Layer

Earth's atmosphere has several layers. The stratosphere includes a layer of ozone, a molecule which contains three oxygen atoms bonded together. Ozone molecules absorb certain frequencies of the sun's rays, including UVB rays. These rays can be harmful to living things. The ozone layer (in the stratosphere) protects us from harmful UVB rays.

In the United States, automobiles are one of several primary producers of carbon dioxide that is emitted into the atmosphere. Imagine cars could run on each of the following fuels. Of the following, which fuel has the greatest potential to minimize the amount of carbon dioxide produced and emitted by automobiles?

Electricity from power plants Since power plants can also operate with non-carbon based fuels, such as nuclear power and wind, electric cars have the greatest potential for minimizing carbon dioxide emissions.

Ozone Depletion

Elements such as chlorine and bromine can disrupt the structure of ozone molecules and break them apart. Among of the most common ozone-destroying compounds are chlorofluorocarbons (CFCs). Unfortunately, these substances are found in many everyday items, such as aerosols like hairspray and spray paint, insulation, air conditioners, and refrigerators. As ozone is depleted, it can create a "hole" in the atmosphere with very low levels of ozone. There is currently an ozone hole over Antarctica. This hole has fluctuated in size, but bans on the use of CFCs in many countries have helped the hole to shrink. A common misconception is that the ozone hole and the greenhouse effect are the same thing. The ozone hole allows more dangerous rays from the sun to penetrate the atmosphere and arrive at earth's surface. The ozone hole is caused by a depletion of ozone in the atmosphere. The greenhouse effect tends to raise earth's temperature and is causes by an excess of various greenhouse gases in the atmosphere. Ozone depletion allows harmful rays to reach earth; excess carbon dioxide leads to potential global warming.

Which of the following is NOT a valid part of a scientific investigation?

Eliminate data outliers. Outliers and unexpected data can provide insights into what is really happening, and should not be eliminated, but can be noted.

When students are conducting an experiment or investigation using glassware, which of the following is the most important piece of safety equipment for them to use?

Goggles would be the most important piece of safety equipment because of the potential for glass breaking and hurting the students' eyes.

When examining the color and clarity of 1 gram of sugar in 30 milliliters of water, which of the following would be the best substitute for a test tube?

Graduated cylinders tend to be narrower than beakers and designed for accurately measuring small amounts of liquid.

Mr. Rawlinson would like to give his students a first-hand look at the different plant responses to stimuli by obtaining a small greenhouse and giving students an opportunity to work in it. Which of the following actions would be best for him to take before choosing his plants?

He should be sure to contact the students' parents to be sure he does not choose plants to which any students are allergic. Student allergies are a concern when working with plants. Mr. Rawlinson should be sure to choose plants to which students have no allergies. *welfare of students is always the top priority and should be demonstrated in the answer you choose!!

Which of the following systems is NOT in equilibrium?

Hot air is forced into a room after the thermostat is adjusted. A room in which the temperature is changing is not in equilibrium.

A student is investigating the growth of Elodea under different light sources. Which of the following is the best research question for this student?

How does the type of light source affect the rate of photosynthesis of Elodea plants? This is the best and most testable research question.

Ethics and Science

Human nature has the innate desire to explore questions about the environment. Scientific discoveries lead to more questions. The progress of scientific research and application is advanced, not only by specific and careful procedures, but many times by making decisions based on a set of standards and the needs of society. When considering what and how to investigate, scientists must consider ethical components of research. Teachers should communicate the importance of ethical practices based on informed choices. Teachers should share with students the discoveries that led to practices of conservation, such as the reuse and recycling of glass, plastic, paper, aluminum, copper, and other metals that are the direct result of focusing on the environmental impact as a response to environmental needs. Other ethical concerns that generate discussion are cloning and DNA sequencing. Students can consider these topics from a variety of perspectives such as economics, privacy, and societal benefit.

Effect of Humans

Human population growth is continual, which causes changes in other populations. As there is an increase of humans, there is an increased impact on the environment and society. These impacts are often mitigated through the use of technology and science, however they cannot be entirely erased. Students must understand these impacts and how they can be lessened through conservation and improvement of technology.

Which of the following activities can contribute to an increase in the carbon dioxide in the Earth's atmosphere? I. the burning of fossil fuels II. volcanic activity III. condensation

I and II The amount of carbon dioxide in the Earth's atmosphere can be increased by the burning of fossil fuels and by volcanic activity.

control

In an experiment, the standard that is used for comparison. a control is neccessary to prove that the results occurred from the changed conditions and would not have happened normally. Only one variable should be manipulated at a time.

Scientific knowledge is continually changing and being added to.

In order for new information to become part of current scientific knowledge, other scientists, often in peer-reviewed journals, must review the data collected by the scientist. If the scientist's methods of data collection, analysis, and conclusions hold up to the questions posed by others, his information becomes valid scientific knowledge.

Proper Data Analysis

In order for scientists to truly accept a claim or a hypothesis, it must be supported by experimental data. This requires testing multiple facets of the issue, conducting several trials to ensure the validity of the results, and reporting data clearly and accurately by several representations if necessary. Some methods of data reporting have limitations which can be overcome by using another method. For example, a bar graph is used for comparing groups, while a line graph is used to show change over time. Presenting information in diverse formats is an important skill, so an accurate portrayal of the information may be shown. Scientists must analyze the data and choose the representation which is most suited to it. Each unique experiment has its own limitations, so it is important to use multiple resources in order to draw conclusions. Since each experiment will require the use of different tools and will therefore provide data in a variety of formats, it is important for scientists to be able to interpret these in order to answer their experimental question. The ability to read graphs, charts, and tables gives scientists a better idea of what the results of the experiment truly mean.

Non-Experimental Investigations

In the course of scientific inquiry, scientists may wonder about things that are almost impossible to test in an experimental setting. That is, it may be very difficult to create controlled conditions and only manipulate one independent variable to measure its effect on the dependent variable. In these instances, scientists may choose to use a non-experimental investigation. Non-experimental investigations may take the form of a survey, an interview or question posed to a large number of people, observations, or analysis of observed behaviors. These types of investigations are often used in social sciences like sociology and psychology. A key difference between experimental and non-experimental investigations is that non-experimental investigations do not have carefully controlled conditions. There are three types of non-experimental investigation: Single-variable research, in which a researcher makes observations before and after the application of a treatment or asking of a question. While this research does have a manipulated variable, the other conditions are not controlled. For example, a researcher may want to determine how well people can read facial expressions. She may show pictures of people with different facial expressions to the subject and record whether or not they can identify the expression correctly. Correlational research, in which the scientist may study two variables, but does not control the rest of the conditions of the study. For example, a researcher may ask students to fill out a questionnaire about how many class activities they participate in along with a questionnaire about how engaged they feel in the classroom. Quasi-experimental research, in which the scientist studies the effects of an independent variable, but chooses the experimental groups rather than assigning them randomly. For example, a scientist studying nutrition education by comparing results between two nursing homes - one with a nutrition education program and one without.

There are three types of variables:

Independent variables are those that the scientist manipulates. There should typically be only one independent variable in each experimental trial. They are typically plotted on the x-axis or used as a label when graphed. Dependent variables are those that depend on the condition or value of the independent variable. These are the factors measured by the scientist. Usually, experiments are conducted in order to study effects on the dependent variable. They are typically plotted on the y-axis when graphed. Controlled variables are those that remain the same across experimental trials. These can include the temperature at which the experiment is conducted, atmospheric conditions, and so forth. The presence of controlled variables ensures that the only factor affecting the dependent variable is, in fact, the independent variable.

A student makes a hypothesis that the period of a pendulum depends upon the hanging weight. The student is provided with string attached to the ceiling, several masses, a ruler, and a stopwatch. The student sets up the pendulum and starts its motion, measuring the time for 10 full cycles. What should be the independent and dependent variables to correctly test the hypothesis?

Independent: mass ; Dependent: time Mass is the independent variable. It is what the student chooses, changes, and controls. Time is the dependent variable. It is what the student measures.

observations

Information gathered by noticing facts and occurrences using your five senses.

Why is it important for scientists around the world to adhere to the same system of measurement?

It allows for easier and more consistent communication of results. A consistent system of measurement allows scientists to compare results more easily and remain consistent in their findings.

Suppose Mike's actual weight is 165 lbs. His scale says his weight is 164 lbs. What can be said about his scale?

It is accurate. This scale is accurate because it gives a weight close to his actual weight.

science is a process of checks of balances

It is expected that scientific findings will be challenged, and in many cases re-tested. often one experiment will be the beginning point for another. While bias does exist, the use of controlled experiments, logical reasoning, and awareness on the part of the scientist, can go far in ensuring a sound experiment. Even if the science is well done, it may still be questioned. It is through this continual search that hypotheses are made into theories, and sometimes become laws. It is also through this search that new information is discovered.

What quality makes evidence reliable?

It is factual and is gathered through concrete means. Reliable evidence is unbiased, concrete data gathered during scientific investigations.

Choose Appropriate Equipment

It is important for scientists and science students to choose appropriate equipment to use in instructional activities and scientific investigations. Some examples of appropriate equipment include a beaker, graduated cylinder, pipette, or Erlenmeyer flask to measure volume; a metric ruler, meter stick, or metric tape measure to measure length; a balance to measure mass, a scale to measure weight, a Celsius thermometer to measure temperature, a stopwatch to measure time, and a computer to record data digitally. When choosing the proper equipment to gather data, it is important for the scientist to consider what the outcome of the investigation might be. For example, if the scientist is comparing the volume of two chemicals produced after a reaction, the results must be fairly precise. Therefore, it would be wiser to use a graduated cylinder rather than a beaker, since the cylinder measures volume more accurately.

Suppose Monica's actual weight is 122 lbs. Her scale says her weight is 99.82 lbs. What can be said about her scale?

It is precise. The scale is precise because it is reporting her weight to hundredths of a pound. It is not accurate, however, because the number it is giving is over 20 percent off from her actual weight.

Where could you find extensive safety information about a hazardous chemical?

MSDS Every hazardous chemical has an MSDS, or material safety data sheet. It contains basic information about the chemical, its associated hazards, how to handle it, how to store it, and what to do if it spills.

In order to investigate the effects of insulation on water as it cools, students place hot water in a beaker that is completely wrapped with insulation. They place a temperature probe in the water and record its temperature as a function of time. In order for the students to draw valid conclusions about the insulation, what else should they do?

Make the same measurements on a second beaker of hot water that has no insulation. To draw a valid conclusion about insulation, the students should perform the same experiment with a control; that is, a beaker without insulation. The only experimental variable should be the presence or absence of insulation.

Measuring Change and Constancy

Many scientific experiments measure change or constancy within a system. It is important for scientists to be able to communicate the results of their experiments clearly with other scientists. Knowledge is grouped in an orderly manner, and measurement systematically organizes information, which makes finding data or making a comparison easier. Different systems of measurement can be used for different purposes. Scientists typically use The International System of Measurement (SI), or metric system, to communicate the results of scientific investigations more clearly. Some experiments occur on very small spans of time and/or distance while others can use a very large span. The metric system makes it easy for scientists to know what scale the scientist is using.

teachers and students should understand that the use of a tool unsuitable to the task or improper tool use can cause inaccurate readings and corrupt data. For example, it is more accurate to use a graduated cylinder and water to take the volume of an irregularly-shaped object, rather than using a metric ruler to measure each dimension. Students should know the proper names and uses of laboratory tools, materials, and equipment including goggles, hand lenses, balances, magnets, timing devices, weather instruments, thermometers, rulers, beakers, spring scales, hot plate, test tubes, meter sticks, compasses, and microscopes.

Many tools need to be handled carefully to avoid damage. For example, microscopes should always be carried with two hands, with one hand on the base on one hand on the neck.

Propagation of Errors

Margin of error increases when multiple measurements are taken and combined. One illustration of this idea is that, using a foot-long ruler measured with increments of 1/16 in, a student determines that the length of the room is 15 feet and its width is 12 feet. Therefore, the perimeter of the room should be 54 feet [perimeter is the total distance around the room, so 2(15) + 2(12) = 30 + 24 = 54]. However, with the smallest unit of measure on each ruler being 1/16 in, each use of the ruler brings in a margin of error of 1/32 in. The possibility of error, therefore, is 15 × 1/32 = 15/32 inches for the 15 foot wall and 12 × 1/32 = 12/32 = 3/8 inches for the 12 foot wall. As such, the margin of error for the perimeter of the room is 2(15/32) + 2(3/8) because the perimeter includes two 15 foot walls each with 15/32 inches of error, as well as two 12 foot walls, each with 3/8 inches of error. 2(15/32) + 2(3/8) = 30/32 + 6/8 = 15/16 + 12/16 = 27/16 = 1 11/16 inches In the end, it can be seen that there is 1 11/16 inches of total potential error on the perimeter calculation of 2(15) + 2(12) = 54 feet measured with the use of a one-foot ruler with the smallest increment of 1/16 of an inch. This margin of error indicates that the total perimeter of the room is 54 feet ± 1 11/16 inches, that is, the actual perimeter of the room is somewhere between 53 feet 10 5/16 inches and 54 feet 1 11/16 inches.

Which of the following scientists won two Nobel Prizes, one in physics and one in chemistry, and discovered the elements Radium and Polonium?

Marie Curie Marie Curie, along with her husband Pierre, discovered Radium and Polonium.

A student performed an experiment on three different types of paper towels. Each of the towels was soaked in a separate beaker, each containing 20 ml of water, for exactly 15 seconds. The towels were removed. What step should be next in the procedure in order to accurately identify the paper towel that absorbed the most water?

Measure the remaining water in each of the three beakers and compare the results. To accurately compare the paper towel absorption, the amount of water remaining in each of the beakers must be measured and compared after removing the soaking paper towels.

A group of students want to find out the specific temperature at which chocolate will begin to melt. To determine the correct temperature, the students would rely on which science processing skill?

Measurement would be used during the experiment to find a specific temperature.

Which of the following units can be used to represent pressure?

N/m2 Pressure is force per unit area. Force units are newtons (N) and area units are square meters (m2) so pressure can be measured in N/m2.

Effects of Natural Phenomena on Climate

Natural events, such as volcanic eruptions, can have drastic impacts on climate. Volcanoes spew ash and soot into the atmosphere that can block the sun and lead to a volcanic winter. A volcanic winter brings lower temperatures worldwide. In 1991, the eruption of Mt. Pinatubo in the Philippines lowered global temperatures for a time. A violent volcanic eruption in 1815 cooled the earth so much that the following year was called "the year without a summer".

live specimens

No dissections may be performed on living mammalian vertebrates or birds. Lower order life and invertebrates may be used. biological experiments may be done with all animals except mammalian vertebrates or birds. No physiological harm may result to the animal. All animals housed and cared for in the school must be handled in a safe and humane manner. Animals are not to remain on school premises during extended vacations unless adequate care is provided. Many laws stipulate that any instructor who intentionally refuses to comply with the laws may be suspended or dismissed.

Which of the following statements accurately reflects a contrast between experimental and nonexperimental research?

Nonexperimental research studies correlations while experimental research studies cause-and-effect. Since there is no manipulation of an independent variable in nonexperimental research, there is no clear method to determine cause-and-effect relationships as in experimental research methods.

Renewable vs Nonrenewable

Nonrenewable resources will eventually run out. One example is fossil fuels, which are made from the remains of dead plants and animals make up the majority of the earth's energy sources. However, human reliance on fossil fuels will not be an indefinite option because of limited reserves. Coal, oil, and natural gas are other relatively abundant and inexpensive sources of nonrenewable energy. Some renewable resources are wind, solar, geothermal, hydroelectric and biomass. Due to the new technology, these resources are creating more efficient means of harvesting energy. It is important to explain the environmental impact pollution from fossil fuels has on the planet and the role they play in climate change.

What Unit to Choose?

Not every unit will make sense to use in every type of measurement situation. Consider 3 different units that could be used to measure an adult person's weight: 2880 ounces, 180 lbs, 0.09 tons The measurement in ounces is a very large number, and the measurement in tons is a very small number, so the measurement is lbs in the easiest to work with. Both the English standard system and the metric system are commonly used for length, weight, and capacity. The English system (sometimes known as the Imperial system) is a system of measurement used in the United States using units such as feet, pounds and ounces. The metric system (sometimes known as SI) is a system of measurement used throughout the world in which the basic units are the meter, the gram, and the liter. In this system, the ratios between units of measurement are multiples of ten. See the chart below for a list of units appropriate for measuring length, weight, and capacity in each system: see screenshot Note that the table "lines up" the two systems by magnitude, but the individual rows are NOT equivalent to each other.

Precision vs Accuracy

Not only can the conversion process create inaccuracies, but human (and machine) error creates another layer of inaccuracy or approximation in measurement.

Form and Function

Objects, organisms, and systems show a dependent relationship between form and function. Form, the shape of an object or system, is directly related to the function. The function, the job or purpose of the system or object, frequently relies on the form. For example, the shape, weight, and bones of a bird's wing are directly related to the function of flight, and the bird's ability to fly depends on its form. Form and function have a complementary nature in a system. Form allows the function to occur, and the function reinforces the need for the specific form. Solar systems, for example, have a massive object at the center in order for the form to take shape as the planets orbit the center. Likewise, the planets would not be able to orbit without the massive object.

Lifestyles and Science

Personal choices concerning fitness and health have a tremendous impact on the physiological and psychological well-being of every individual. Many factors in society affect the choices made regarding fitness and health including media, family practices, and peer influence. Students should be able to understand that adequate rest, dietary choices - including nutritionally balanced meals and healthy eating habits - regular exercise, and avoiding the use of drugs and alcohol lead to long-term physical and psychological health. The US FDA's current dietary guidelines use the "My Plate" image to show the relative portion sizes of each type of food for a balanced meal.

Key Science History

Physical and Space Science Nicolaus Copernicus - sun is at the center of the solar system, not the Earth (heliocentricity) Galileo Galilei - Made a good telescope, discovered Jupiter's moons, and furthered Copernicus' idea of heliocentricity. Also talented at math and credited with the scientific method. Sir Isaac Newton - laws of motion and discovery of gravity Albert Einstein - theory of relativity (related to gravity) Daniel Bernoulli - principle to explain the conservation of energy in fluids Biology and Chemistry Gregor Mendel - father of genetics Louis Pasteur - discovery of airborne diseases and vaccines Charles Darwin - theory of evolution Marie Curie, along with her husband Pierre - discovered Radium and Polonium Rosalind Franklin - used x-ray crystallography in her research on the DNA molecule Dmitri Mendeleev - created the basis for today's periodic table

precision

Precision is a way of determining and discussing what level of accuracy is possible based on the tools used. In math, the word tolerance is defined as the amount of error that is allowed. Formally, accuracy is considered to be ±½ of the smallest measuring unit. Therefore, a ruler marked in ¼ inch increments, for example, is only accurate to ± 1/8 inch (because one-half of one-fourth is one-eighth); a scale that measures weight in grams is accurate to ±1/2 gram; when using a protractor marked in degrees, the accuracy is ±½ degree. Therefore, the smaller the mark on a measuring tool, the greater the precision.

Dynamic

Property of a system to constantly change in response to a stimulus volcanic eruptions from geothermal pressure

Which type of investigation has one manipulated variable, but the researcher chooses experimental groups rather than assigning them randomly?

Quasi-experimental research Quasi-experimental research involves the researcher choosing experimental groups. For example, a researcher may choose two different schools and implement a healthy eating campaign in one school and not in the other.

A sixth-grade science teacher wants to test student engagement levels in response to different activities. She gives students in her first period and last period classes a questionnaire. The first period class participates in a think-pair-share activity with partners. The last period class listens to a lecture and takes notes. Both classes cover the same material. Both classes then fill out the questionnaire again. Which type of research does this illustrate?

Quasi-experimental research Since the teacher did not randomly assign students to the classes, this is an example of quasi-experimental research.

Acid Rain

Rain with a lower pH than neutral. Acid rain is corrosive to many substances, including rocks. Often caused by pollution. sulfur dioxide dissolves in the water droplets of clouds to make sulfuric acid

Which of the following would best help students learn to protect themselves against potential health hazards in the laboratory?

Regularly require students to wash their hands after a lab experience. Requiring hand washing after touching equipment can lead to good safety habits for all students.

Science is Always Changing

Remember that the process of science involves starting with a question, developing a testable hypothesis, designing an experiment, collecting data, analyzing results, and determining a conclusion. This process is called the scientific method and is the basis for all scientific knowledge. Often, though, this process is not linear, and not all scientific investigations involve all of these steps.

What is the difference between renewable and nonrenewable resources?`

Renewable resources are replenished faster than or at the same rate that they are used. Nonrenewable resources cannot be replenished as fast as they are used. Renewable resources include biomass, hydropower, wind power, and solar power. Nonrenewable resources include fossil fuels like petroleum, natural gas, and nuclear energy.

What is the most important reason for repeatability in scientific investigations?

Repeatability decreases the impact of human error, increases the reliability of results, and solidifies scientific law. This is the most important reason for repeatability in scientific investigations.

Experimental Investigation

Researchers assign subjects in the sample to certain treatments, then observe the effects of the treatment. Can show causation (cause and effect). Does using algebra tiles during instruction help freshman students learn how to solve equations?

Scientific Communication

Results of scientific investigations are communicated to the global scientific community in order to share the discovery. This allows other scientists to verify the results and the public to make use of the new information. Results of students' scientific investigations should also be properly collected and displayed in charts, graphs, tables, and descriptors. Science students should learn to communicate data in writing, by drawing pictures, and through discussion. Visuals are used to help the reader make sense of observations and measurements collected during the experiment. When recording data, students should identify the manipulated (independent) and responding (dependent) variables in the experiment and observe common patterns that occur in multiple trials completed in the investigation. Students should determine the appropriate type of graph to display the data by looking at the kind of information collected during the investiga

A chemistry teacher has planned an investigation on dissolution rates of solutions. The day before the lesson, she reviews the lab safety rules. Which rule does she likely review?

Safety goggles must always be worn when working in the laboratory to prevent any chemicals from contacting the eyes.

When deciding to house a live animal in the classroom, the risk of a potential health hazard to the student or animal must be weighed against the educational value added. What guidelines must first be considered to address this potential hazard, prior to making a choice of getting the animal for the classroom?

Safety standards require that any live animal in the classroom must be fed and kept in sanitary conditions every day. Although the care and comfort of the animal is important, the safety concern with regards to the students is the teacher's first priority.

Why is learning the scientific process, such as collecting evidence, making models, and constructing explanations, as important to a science lesson as learning content?

Science processes unify science disciplines and phenomenon. Science processes are unifying concepts that span across the science disciplines and phenomenon. Once a student learns how science is done, they can apply the processes to other scientific concepts, including their own investigations. Understanding the process of science helps students evaluate the research and conclusions of others.

Dimensional Analysis - Conversions in Science

Science uses dimensional analysis to compare many things. In the example below, it is used to determine which reactant creates less product and thus is the limiting reagent. Notice that the units all cancel to what is desired. learn and practice the steps and elimination strategies As long as each fraction used is true (equals 1), you can convert 1 unit into many different units.

Which of the following is a key characteristic of scientific inquiry?

Scientific theories are open to change as new information is discovered. Science is a field that is open to change as new information is discovered.

Students perform an investigation to compare the relative specific heats of sand, water, and soil. They fill plastic cups with the same mass of each material, place a temperature probe in each sample, and put the samples the same distance beneath identical flood lamps. Students record temperature data for 2 minutes while the lamps are on, and continue recording data for 1 minute after the lamps are turned off. Which of the following is the dependent variable in this experiment?

The change in temperature of the materials is the dependent variable because it will vary depending upon the type of material used.

In science, the word "theory" does not mean an idea or a hunch.

Scientific theory is developed when scientists use scientific knowledge and present a proposed explanation for the observed pattern. Scientific theories also do not become scientific laws. These two terms mean very different things. Take gravity for instance; the law of gravity states that, in simple terms, what goes up must come down. It summarizes everything we know about gravity into a general statement that applies to every situation. The theory of gravity consists of all the best explanations of why gravity works. The law of gravity and theory of gravity are both scientific fact, but they are different ways of looking at gravity. Scientific theories do not become scientific laws.

Experimental Investigations

Scientists use a variety of investigation types when trying to learn more about the natural world. Sometimes scientists carry out experimental investigations in deliberately controlled conditions, such as in laboratories. Experiments typically have variables, or factors affecting the outcome.

Mr. Gann sees a line graph featured in a news article. What should his next steps be to verify this data?

Search for further data on the same topic in peer-reviewed scientific journals. Searching for verification from other reliable sources will confirm whether the reported results are accurate and the conclusions are valid.

The Metric System

Since a key tenet of the scientific method is for the results to be tested and retested by other scientists, it is important for mathematicians and scientists to have a universally-communicable method of reporting data. This method is known as the International System of Units (SI) or the metric system. The metric system is based on powers of ten. The base units include meters, liters, and grams, and each other unit is given a prefix based on its factor of ten. To convert between units, all that is required is to multiply or divide by ten. The table below lists a mnemonic phrase to help remember the prefixes, their factors of ten, and their abbreviations King Henry Died By Drinking Chocolate Milk

Human Impacts

Since humans are a part of their ecosystems, it is only natural for us to have an impact. Human impacts on ecosystems include pollution, hunting, selective breeding, farming, deforestation, fragmentation, and urbanization. These activities tend to decrease biodiversity. Humans can have a positive impact on ecosystems. Laws are put in place to protect millions of acres of land in the United States alone. Environmentalists and conservation biologists carefully monitor wildlife populations and ensure that the ecosystem maintains balance. While it is impossible to have no impact on ecosystems, it is important for us to try to minimize our negative impact on the environment and wildlife. Reducing the burning of fossil fuels, using fewer paper products, and reducing our need for gasoline by carpooling are examples of ways to reduce our harmful impact on ecosystems.

Which type of investigation has one manipulated variable, but no other controlled conditions?

Single-variable research has only one manipulated variable and no other controlled conditions. A researcher making observations before and after asking a question is an example of this type of research.

Science in the elementary classroom provides an opportunity for students to investigate the natural world, both in the classroom and outdoors. The methods of inquiry require proper planning and implementation of these investigations. The safe use of tools, materials, and equipment is a primary focus. Teaching laboratory safety standards to students prior to participation in any investigation is required, as is providing them with information regarding proper safety rules and procedures for the science classroom.

Some common safety practices to teach include: Never put chemicals back into the container to avoid contamination Properly dispose of excess chemicals in liquid waste bottles. Always wear safety goggles when working with glass, chemicals, or fire Wash hands before and after experiments Direct the openings of containers away from faces Never use/touch chipped or broken glass Do not eat or drink in the lab Never directly smell chemicals; instead, waft the air toward the face Do not taste chemicals Keep water and objects away from electrical outlets Always notify the teacher in the case of a spill or accident.

Dimensional Analysis - Multiple Unit Fractions

Sometimes multiple unit fractions will be multiplied in order to drop a particular unit and bring in another. Several fractional forms of 1 may be necessary, especially when converting from a comparatively large unit of measure (such as gallons) to a much smaller one (like milliliters), and also when changing from one system of measurement to another (English standard to metric, for instance).

The method is effective because units of measure appearing in both the numerator and denominator are canceled (divided into each other). The remaining measures are attached to the solution to the problem and provide the correct unit for the answer.

Steps to convert using dimensional analysis: Write the given value and units Identify the conversion factor using the given unit and the next unit. Write it with the given units on the bottom. Continue writing conversion factors until the goal units are on top. Solve by dividing the product of the numerators by the product of the denominators.

Precision vs Accuracy

Students should be able to read and record data from laboratory equipment and scientific instruments using precision and accuracy.

Carl von Linne (Linnaeus)

Swedish botanist who proposed the modern system of biological nomenclature (1707-1778) he was also a physician and zoologist. known for his contributions in ecology and taxonomy. Linnaeus is famous for his binomial system of nomenclature in which each living organism has two names, a genus and a species name. He is considered the father of modern ecology and taxonomy.

System Changes

Systems are dynamic, and they will not always have the same characteristics. They experience changes which affect their behavior and composition. These random changes in biological, physical, or geological systems may be abrupt or occur gradually over a period of time. If a system is not changing, it is said to be in equilibrium. Examples of changes in ecosystems are natural phenomena. Unbalanced natural forces cause these phenomena. These natural events produced by natural forces cause noticeable changes to the earth's surface. Some examples of natural phenomena are volcanic eruptions, earthquakes, hurricanes, thunderstorms, lightning, tornadoes, and tsunamis. These changes drastically affect the system in which they occur. Recovery from these events can take many years. Evolution is an example of a series of changes in a system. Random genetic mutations give rise to traits which are more or less beneficial to those organisms. After a series of changes, those more suitable genes are passed down, and the organisms with those genes survive. Teachers should compare the present form and function of systems with the direct result of evolution in some form and identify what causes the system to react to forces and change. A common example of this is bird beaks. Birds of the same species will have different shaped beaks based on the food available in their habitat. Students can look at pictures of the species over time and see how the beak shape changed to accomodate the diet.

Which of the following is not true about systems?

Systems remain constant and unchanging. Systems are dynamic; they do not remain constant and unchanging.

Chemical labels provide appropriate handling, disposal, care, and storage procedures.

Teachers should keep a physical or digital copy of the Material Safety Data Sheet for each chemical or substance used in the classroom. Safety symbols and their meanings should be taught.

Which of the following is not true regarding global warming and climate change?

Temperatures around the world are universally increasing. Temperatures may decrease in some parts of the world. For example, when the ice caps melt, they release cooler water into the ocean, which reduced the temperature in those locations.

Heliocentricity

The accepted astronomical model that the sun is at the center of our solar system. The theory was put forth by Copernicus in 1543 and expanded upon by Galileo in 1632.

Students should understand that following the scientific method often results in a "feedback loop", where the results lead to more possible hypotheses and continued testing.

The goal of a science teacher is to provide a learning environment designed to encourage opportunities for hands on experiments which lead students through the process of the scientific method. Making observations and collecting data provides a foundation for scientific explanations. Student explanations should include terms such as hypothesis, experiment, data, and conclusion. Logical explanations need to incorporate evidence gathered from the experiment, but also rely on existing scientific knowledge. The more hands-on and inquiry-based answer is usually the correct one.

Evidence and Models

The goal of scientific research is to explain and predict behavior using factual evidence. This includes data gathered from experiments, measurements taken during experimentation, and observations made using the five senses. Evidence gathered during the course of scientific experiments can be translated into a model. Models are mathematical, physical, or visual representations of scientific phenomena. They help scientists understand and demonstrate how things work as well as explain events which may or may not be directly observable. Examples of models include mathematical formulas and drawings of the cycles, such as the carbon cycle. These ideas - models, relying on factual evidence, and using these to provide explanations of phenomena - are universal across scientific disciplines. It is important for students to understand that scientific processes, such as proper investigative technique, taking accurate measurements, and understanding systems as groups of related parts rather than entities themselves, provide a framework for all scientific investigation. Scientific endeavors are united by these principles regardless of their focus or discipline.

Evolution

The gradual change in populations over time tortoise neck length changing over time in response to changing available vegetation

Biodiversity

The number of different types of species in an area A rainforest has higher biodiversity than the artic.

Scientific knowledge is continually changing and being added to.

The process of science does not prove absolute facts. Instead, it rules out possible explanations, eventually leaving the best explanation as scientific knowledge, or scientific fact. Because of this, scientific knowledge can easily change when the current explanation does not fit with new evidence. Since technology advances at a rapid pace, it is important for scientists to reassess their findings periodically. Better evidence may be obtained when better technology becomes available.

which of the following pieces of lab safety equipment should be used in case of a chemical spill?

The safety shower can be used to wash chemicals off a person's body.

The Scientific Method Unifying concepts in science create a consistent framework about how scientific evidence should be organized, carefully documented, quantified as much as possible, and have the ability to be repeated by other scientists. The steps used to ensure high-quality scientific research are known as the scientific method.

The scientific method involves using deliberate steps to solve a problem while gathering data to reach a conclusion.

System

The set of objects under study. Everything else is the environment. living organism, solar system

Systems

The size and complexity of the universe and all it contains make it difficult to comprehend all at once. In order to make it easier to investigate, teachers should explain how scientists divide the world into small portions, referred to as systems, which consist of related objects. These systems might be comprised of parts of a whole, organisms, machines, particles, galaxies, transportation, education, ideas, and numbers. Systems are made up of matter and energy that are constantly interacting. Energy is never created or destroyed, rather it changes from one form to another. This movement of energy causes matter to cycle and interact. Students need to understand that systems have parts, input, output, boundaries, feedback, and can be identified in every branch of science. Some systems to be included in the explanation of life science are biological systems of classification, and the structure of an organism. Earth and space science focuses on the solar system, and chemistry has the periodic table, which is a system of elements organized according to similar properties. Systems, when changed, can exhibit different feedback, both positive and negative. Negative feedback results when an input changes the system, but the system will eventually correct back to the original state in its output, or results. Body temperature is an example of a negative feedback mechanism. If humans get hot, we sweat to cool off. If we get cold, we shiver to warm up. The input (change in temperature) causes the body to respond in a way to mitigate the change. Positive feedback occurs when a change to the system creates further change in the same direction. An example is global warming. As the earth warms and polar ice melts, less sunlight is reflected back into space, because open water absorbs much more energy than an ice sheet does. The warmer water melts more ice and the cycle continues forward, reflecting less sunlight as more ice melts.

Use of animals in research

The use of animals in biological research has expedited many scientific discoveries. Animal research has allowed scientists to learn more about animal biological systems, including the circulatory and reproductive systems. One significant use of animals is for the testing of drugs, vaccines, and other products such as perfumes and shampoos. before use of consumption by humans along with the pros of animal research, the cons are also very significant. The debate about the ethical treatment of animals has been ongoing since the introduction of animals in research. Many people believe the use of animals in research is cruel and unnecessary. Animal use is federally and locally regulated. The purpose of the institutional animal care and use committee (IACUC) is to oversee and evaluate all aspects of an institutions's animal care and use program.

How many hectoliters are in 45 kiloliters?

There are 450 hectoliters in 45 kiloliters because 1 hectoliter is equal to 100 liters. \frac{1 \text{ hl}}{.1 \text{ kl}} = \frac{x \text{ hl}}{45 \text{ kl}}.1 kl1 hl​=45 klx hl​ see screenshot

Types of Models

There are many forms of models - physical objects, plans, mental constructs, and computer simulations. The dimensions of a model can be increased or decreased based on the needs of the observers. Models can be very useful for visualizing or understanding abstract or hard-to-observe phenomena. There are three main types of models: mathematical, physical, and conceptual. Mathematical models, such as the formula for calculating the velocity of an object, can be used when it is not necessary to visualize the object itself. Physical models, such as a scale sculpture of the human ear, can be used when studying the form of an object. Conceptual models, such as a diagram of the carbon cycle or the Krebs cycle, can be used to understand complex or abstract systems or series of events. While models can be valuable teaching tools, teachers should communicate their limitations, including size, properties, materials, and constant modifications needed to closely reflect the earth's forces and what is happening in the world. Sometimes models do not paint the full picture, and it is necessary to combine several models to get a complete understanding of the topic. In other instances, models may be revised as new information becomes available. For example, as our understanding of the atom has changed, our method of modeling the atom has also changed. Even today, scientists use different models of the atom when discussing different properties.

Nuclear power plants use fission reactions to generate electricity. The by-products of these reactions include long-lived isotopes that must be contained in a way that does not damage the environment. Which of the following is the primary danger associated with these by-products?

They are radioactive and can produce radiation poisoning. The by-products of fission are highly radioactive isotopes. The effects of exposure to radiation include radiation poisoning.

Errors in Measurement

To decrease the margin of error - how close the measurements are to the correct or expected value - and to ensure the accuracy of the measurements, scientists should take at least three trials of a series of measurements in every investigation. Repeated measurements reveal the margin of error and allow scientists to see how close their data is to the true value. Once all trials are complete, scientists can average their measurements to give an overall picture of the data and account for random deviations. If possible, trials with outliers should be replicated. For example, if data has an overall tight correlation but one data point is deviating, re-run the trial for that independent variable value. A common misconception students have is that "error" means "mistake." A good example of the proper procedure of using three measurements is timing a race with a stopwatch. Human reaction time will cause the measurements to differ, and an average is used to approximate the true value. While there is a degree of error in the measurement, the people didn't make a mistake. Students should determine which type of measurement is the most appropriate to what they are investigating, and after recording the length, mass, volume, or time, the appropriate metric unit must be included. To reduce inaccuracy due to rounding, it is important for values to be rounded only after calculations are complete. To ensure accurate measurement in the lab, solutions are read at eye-level in glassware at the bottom of the meniscus, which is the downward curve on the surface of a liquid caused by the adhesion of the liquid on the glassware. Balances should be tared, set at zero prior to use.

Proper Handling of Specimens

When caring for and handling specimens and organisms, students should follow ethical and safety procedures and handle animals only when necessary. Classroom animals must meet safety requirements such as not being toxic or causing a danger to students. Classroom pet cages should be cleaned regularly with household bleach. Teachers should check for any students having allergies before choosing a classroom pet. Students should be taught to wash hands before and after any activity involving plants, animals, or soil. All microorganisms should be treated as pathogens. Disposal of non-carcinogenic or non-corrosive contaminants should be in a double-layered plastic bag and fastened securely with a wire tie.

Which of the following is the appropriate piece of safety equipment to use if chemicals are splashed in someone's eye?

When chemicals get into someone's eyes, the best safety equipment to use is the eyewash station. Eyes should be flushed for a minimum of 15 minutes.

Sometimes, as in medical trials, scientists will carry out trials with many different subjects at the same time. In these instances, scientists will study an experimental group, which receives the treatment being studied, and a control group, which does not receive a treatment. The effects on the groups are compared at the end of the trial.

When conducting an experiment, it is important for scientists to carry out multiple trials. The more experimental trials the scientist conducts, the more valid the results will be. This ensures that the results gathered from one experiment are reliable and are not an outlier

developing proposed explanations

When developing proposed explanations, the students should be able to express their level of confidence in the proposed explanations and point out possible sources of uncertainty and error. When formulating explanations, it is important to distinguish between error and unanticipated results. Possible sources of error would include assumptions of models and measuring techniques or devices.

When smelling a test tube to determine whether it has been rinsed after containing a strong ammonia solution, it is important to:

Whenever smelling equipment that once held chemicals, waft the air above the test tube toward your face to obtain a scent without inhaling harmful chemicals. To "waft" means to wave your hand above the test tube opening, pushing some of the air toward your nose.

Human Effects on Global Climate Change

While the average global temperature has fluctuated in the past, it has remained relatively stable for several thousands of years. In recent years, however, it has begun to rise again. The burning of fossil fuels, such as petroleum, releases carbon dioxide. The increase of this gas in the atmosphere is causing an imbalance that can disrupt the equilibrium of the carbon cycle. Carbon dioxide is a greenhouse gas, and the release of it into the atmosphere traps solar energy and increases the greenhouse effect, raising Earth's overall temperature, leading to large-scale climate change (formally known as global warming). Global warming is also known as global climate change because the climate everywhere is changing (not necessarily warming.) The greenhouse effect is increased by feedback loops. As the earth warms, polar ice caps and glaciers melt, resulting in fewer reflective surfaces. The energy in sunlight, which might have reflected from the ice, is instead absorbed by the darker water. As temperatures rise, soil microbes become more active and more carbon is released into the atmosphere due to an increase in decomposing vegetation. Some scientists warn we will soon reach a point of no return. Rising global temperature could greatly impact society. For example, rising sea levels could cause significant flooding of coastal urban areas. Changes in precipitation and other climate patterns will affect farming, as well as plant and animal habitats. A common misconception people have about global warming is that the temperature everywhere on Earth is increasing. While the average global temperature is increasing, this has varying effects in specific locations. For example, when the overall temperature rises, glaciers and ice sheets can melt, which releases cold water into oceans and can cool the immediate area surrounding the melted ice. By using more clean energy, like solar power or hydroelectric power, humans can reduce their impact on global climate change. Reducing the emissions of greenhouse gases is a global issue, affecting economies, politics, and cultures around the world. For example, many developed nations have banded together to enact laws to reduce these emissions, but other nations continue to grow in their use of fossil fuels.

Human Influences on Climate

`Human consumption of resources and pollution of the air, land, and water affect the Earth's natural cycles, including carbon, water, and nitrogen. This human activity can have an effect on local and global climates. Locally, human activities cause the temperatures in cities to be higher than those of surrounding rural areas. Dark roof and roads trap more of the sun's energy and radiate it to the surroundings. Waste heat from energy usage tends to raise the temperature near cities. Globally, factories emit sulfurous gases, and other products into the atmosphere which can lead to acid rain. The use of fossil fuels like petroleum in vehicles, power plants, and factories puts more carbon dioxide into the atmosphere, causing average global temperatures to rise, perhaps catastrophically. The increase in temperature also affects the amount of water evaporation, which impacts the amount of precipitation that falls to the ground. When humans can divert rivers for irrigation, this decreases the amount of freshwater flowing to the ocean. Besides impacting the cycling of water, humans also influence the quality of the water itself. There is a limited amount of freshwater on Earth, and pollution and the careless dumping of waste and oil into fresh water destroys water quality and affects all life.

Mr. Anderson assigns a group of students to research and present rainfall disparities between the Sahara Desert and the Amazon Rainforest. Which of the following graphs would be most appropriate for the students to use?

a bar graph A bar graph is the best answer. A bar graph is best for comparing amounts between two or more categories.

Proper Tool Use Students should choose the appropriate equipment to use in instructional activities. Some examples of appropriate equipment include:

a beaker, graduated cylinder, pipette, or Erlenmeyer flask to measure volume a metric ruler, meter stick, or metric tape measure to measure length a balance to measure mass a scale to measure weight a Celsius thermometer to measure temperature a stopwatch to measure time a computer to record data digitally

Buret

a buret is used to dispense precisely measured volumes of liquid. A stopcock is used to control the volume of liquid being dispensed at a time.

empirical evidence

a central concept in science is that all evidence is empirical. This means that all evidence must be is observed by the five senses. The study phenomenon must stage of scientific inquiry involves repetition. By repeating the experiment you can discover whether or not you have reproducibility. if results are reproducible, the hypothesis is valid. If the result are not reproducible, one has more questions to ask. with confidence in the proposed explanations, the students need to identify what would be required to reject the proposed explanations. Based upon their experience, they should develop new questions to promote further inquiry.

psuedoscience

a collection of beliefs or practices mistakenly regarded as being based on scientific method- not warranted - fake science (hearsay- witchcraft- ailens)

Inference

a conclusion based on evidence, observation, and reasoning

control

a control is an extra setup in which all the conditions are the same except for the variable being tested.

Outlier

a data point either much larger than or much smaller than the other data points in the set.

Mattias Scleiden

a german botanist is famous for his cell theory. He observed plant cells microscopically and concluded that the cell is the common structural unit of plants. He proposed the cell theory along with schwann, a zoologist, who observed cells in animals.

Mr. Orlando is teaching a unit about density, which is the amount of mass in a given volume. He would like students to practice measuring the density of various objects. Which of the following lists of equipment should Mr. Orlando provide to his students?

a graduated cylinder and a balance Density is the relationship between the mass of a substance and its volume. A graduated cylinder will help the student measure volume and a balance will help the student measure mass.

pie chart

a graph in which a circle is divided into sectors that each represent a proportion of the whole. Pie charts are helpful when displaying the relative distribution of categories.

line graph

a graph that uses one or more lines to show changes in statistics over time or space (histogram) line graphs are used to illustrate the relationship between two variables.

Experimental Group

a group of specimens in an experiment to which a change is made; receives the experimental treatment In an experiment investigating the effect of talk therapy on alleviating depression, the group receiving the medicine and the therapy would be the experimental group.

Control Group

a group of specimens in an experiment to which no change is made; does not receive the experimental treatment In an experiment investigating the effect of talk therapy on alleviating depression, the group receiving only the medicine would be the control group.

Which of the following is an example of a scientific model?

a mathematical formula A mathematical formula is an example of a mathematical model - a representation of phenomena.

Different systems of measurement are used for different purposes. Scientists typically use the metric system to communicate results to other scientists. Which of the following describes a situation when a scientist might use a different system of measurement to communicate data?

a meteorologist reporting the temperature to the viewing audience Scientists all over the world communicate measurement using the metric system of measurement. However, when communicating results, it is important to make sure the recipient of the information is familiar enough with the measurement to understand the communication. A meteorologist reporting weather to a viewing audience who understands English standard measurement would use the English unit for temperature (degrees Fahrenheit).

Ozone

a molecule containing three oxygen atoms; absorbs some of the sun's rays to protect Earth's surface

Fossil Fuels

a natural non-renewable fuel source. derived from underground, fossilized (petrified) remains of living organisms. natural gas, petroleum, coal

Volcanic Winter

a period of time in which global temperatures are lowered due to a severe volcanic eruption spewing ash and other products into the atmosphere; these products block some of the sun's rays from reaching Earth's surface and consequently lower temperatures

Which of the following is not an example of a scientific model?

a piece of lunar rock A piece of lunar rock is not a model; it is an actual sample.

Which of the following is the best definition of a hypothesis?

a predicted outcome based on an observation that can be further tested by experimentation This is the definition of a hypothesis.

Scientific Theory

a proposed explanation for a phenomenon which may not be testable Darwin's Theory of evolution

Scientific Law

a proven explanation for a phenomenon Newton's Laws of Motion

Conceptual Models

a representation of a system using diagrams or drawings to explain complex or abstract systems or processes a diagram of cellular respiration

Non-Experimental Investigation

a research method in which conditions are not carefully controlled; the scientist may study an independent and/or dependent variable, but does not control the other factors in the investigation survey, observation, analysis of observed behavior

Output

a result of input into a system human shivering to increase temperature when it is cold

Koch's Postulates

a sequence of experimental steps for directly relating a specific microbe to a specific disease, they state that the same pathogen must be found in every diseased person; the pathogen must be isolated and grown in culture, the disease is induced in experimental animals from the culture and the same pathogen must be isolated from the experimental animal.

Scientific Method

a series of deliberate steps by which scientists observe, hypothesize, test, analyze data, and communicate results

240 flashcards- accuracy

a set of different values which are close to a true value. When measuring with a tool, the tool is accurate to 1/2 of the smallest measuring unit a group of darts near the target

Precision

a set of different values which are close to one another a group of darts near one another

Physical Models

a smaller or larger replica of an object done to scale a physical model of an atom

International System of Units (SI) / The Metric System

a standard system of measurement based on powers of 10. meters, liters, grams

Material Safety Data Sheet (MSDS)

a standardized information sheet for a substance; includes information about health risks, safe disposal and cleanup of spills, and environmental risks

Conclusion

a summary of the results of an experiment; states whether the initial hypothesis was rejected or supported

English system / Imperial system

a system of measurement used in the United States using units such as feet, pounds and ounces

Which of the following models would be most appropriate for a geologist to use to show the locations and relative elevations of mountain ranges in the United States?

a topographic map of the United States A topographic map of the United States best illustrates the locations and relative elevations of mountain ranges in the United States.

Positive Feedback

a type of input into a system in which the result causes the system to continue on the path in which it was headed before the input global warming

Negative Feedback

a type of input into a system in which the result causes the system to return closer to previous conditions body temperature regulation

independent variable

a variable (often denoted by x ) whose variation does not depend on that of another.

dependent variable

a variable (often denoted by y) whose value depends on that of another.

Controlled Variable

a variable that is kept stable throughout the experiment, across control and experimental groups, to ensure that any difference in the dependent variable is because of the independent variable. In an experiment investigating the effect of amount of light on plant growth, the amount of water would be a controlled variable since it is not being studied.

Independent Variable

a variable that is manipulated by the scientist conducting the experiment to see if that causes a change In an experiment investigating the effect of amount of light on plant growth, the amount of light would be the independent variable since it affects the amount of growth.

Dependent Variable

a variable that is measured by the scientist conducting the experiment In an experiment investigating the effect of amount of light on plant growth, the plant growth would be the dependent variable since it depends on the amount of light.

Histogram

a visual representation of data which compares frequencies of different numeral intervals

bar graph

a visual representation of data which compares values in different categories the number of people who prefer each genre of movie

line graph

a visual representation of data which shows change over time or in response to a manipulated variable

scientific law/law of nature/ principle

a well-tested and widely accepted description of what we find happening repeatedly and in the same way in nature- lasts longer more reliable- more experimental data to support it

scientific theory

a well-tested explanation for a set of observations or experimental results or proven hypothesis.

Which of the following is a key component to living a healthy lifestyle?

adequate water, nutrition, and exercise Adequate water, nutrition, and exercise are key components of a healthy lifestyle.

In a spectrophotometry experiment, students add different amounts of dye to the same amount of water. Students then measure the absorbance of each solution. What is the dependent variable in this experiment?

absorbance- a dependent variable is one that is tested and measured in an experiment. in this case, the absorbance is the dependent variable.

accuracy and precision

accuracy is the degree of conformity of a measured, calculated quantity to its actual (true) value. Precision also called reproducibility or repeatability and is the degree to which further measurements or calculations will show the same or similar results. accuracy is the degree of veracity while precision is the degree of reproducibility. The best analogy to explain accuracy and precision is the target comparison. repeated measurements are compared to arrows that are fired at a target. Accuracy describes the closeness of arrows to the bull's eye at the target center. Arrows that strike closer to the bull's eye are considered more accurate.

posing a question

although many discoveries happen by chance, the standard thought process of a scientist begins with forming a question. The more limited the question, the easier it is to set up an experiment to answer it.

Hypothesis

an informed prediction (made based on previous observations) for a phenomena. Should be testable. If we give plants more fertilizer, they will grow taller.

Data table

an organized way to display data that presents the results in labeled rows and columns t-chart

Global Warming / Climate Change

an overall increase in average global temperatures due to the greenhouse effect (the increasing amount of carbon dioxide in Earth's atmosphere trapping more heat)

dissections

animals that are not obtained from recognized sources should not be used. Decaying animals or those of unknown origin may harbor pathogens and or parasites. Specimens should be rinsed before handling. Latex gloves are desirable. If gloves are not available students with sores or scratches should be excused from the activity. Formaldehyde is a carcinogen and should be avoided or disposed of according to district regulations. students objecting to dissections for moral reasons should be given an alternative assignment.

The ozone hole is above which part of the Earth?

antarctica The ozone layer is the thinnest over Antarctica. This is where the ozone hole forms.

light microscopes

are commonly used in laboratory experiments. several procedures should be followed to properly care for this equipment: clean all lenses with lens paper only carry microscopes with two hands; one on the arm and one on the base. always begin focusing on low power, then switch to high power. store microscopes with the low power objective down. always use a coverslip when viewing wet mount slides. bring the objective down to its lowest position then focus by moving up to avoid breaking the slide or scratching the lens. wet mount slides should be made by placing a drop of water on the specimen and then putting a glass coverslip on top of the drop of water. Dropping the coverslip at 45 degree angle will help in avoiding air bubbles. total magnification is determined by multiplying the ocular (usually 10x) and the objective (usually 10x on low, 40x on high)

descriptive studies

are often the first form of investigation used in new areas of scientific inquiry. The most important element in descriptive reporting is a specific , clear and measurable definition of the disease, condition, or factor in question. Descriptive studies always address the five Ws: who what when where and why. They also add an additional "so what?" descriptive studies included case reports, case series reports, cross-sectional students, surveillance studies with individuals, and correlational studies with populations. Descriptive studies are used primarily for trend analysis, health-care planning, and hypothesis generation.

random errors

are statistical fluctuations in the measured data due to the precision limitations of the measurement device. Random errors usually result from the experimenter's inability to take the same measurement in exactly the same way to get exactly the same number.

skill 3.6 develops, analyzes, and evaluates different explanations for a given scientific result

armed with knowledge of the subject matter, students can effectively conduct investigations. They need to learn to think critically and logically to connect evidence with explanations. This includes deciding what evidence should be used and accounting for unusual data. Based upon data collected during experimentation, basic statistical analysis, and measures of probability can be used to make predictions and develop interpretations.

skill 1.2 procedures and sources of information regarding the appropriate handling, use, disposal, care, and maintenance of chemicals, materials, specimens, and equipment

as the teacher you should utilize a MSDS whenever you are preparing an experiment. It is designed to provide people with the proper procedures for handling or working with a particular substance. MSDS's include information such as physical data (melting point, boiling point, etc. Toxicity, healthy effects, first aid, reactivity, storage, disposal, protective gear, and spill/leak procedures. These are particularly important if a spill or other accident occurs. You should review the MSDS, commonly available online and understand the listing procedures. MSDS are available from the company of acquisition or the internet. The manuals for equipment used in the lab should be read and understood before each use

The physical education teacher conducts a poll about the games students would like to play during field days. The teacher lists eight games and records how many students respond "yes" or "no" to each game. Which graph will best represent all the data on the same plot?

bar graph A bar graph compares data from different categories. This is the best choice because it is easy to see the relative number of "yes" and "no" votes for each game.

Which type of graph or chart would be best used to show comparisons between the volume of water drunk by athletes competing in two different sports?

bar graph Bar graphs are used to compare populations or groups. This is the correct graph.

Graphs used to display categorical data:

bar graph line graph pie chart

Sally Ride's scientific career was highlighted when she:

became the first American woman in space. In 1983, Sally Ride became the first American woman, and the third woman in the world, to go into space.

Andreas Vesalius (1514-1564)

belgain anatomist and physcian whose dissections of the human body and descriptions of his findings helped to correct the misconceptions of science. the npls vesalius wrote on anatomy were the most accurate and comprehensive anatomical texts to date.

Which of the following is an example of a negative feedback system?

body temperature regulation Body temperature is a negative feedback system, with the result of the feedback being a return closer to the normal status of the system.

systematic errors

by contrast, are reproducible inaccuracies that are consistently in the same direction. systematic and random errors refer to problems associated with making measurements. mistakes made in the calculations or in reading the instrument are not considered in error analysis.

Which of the following behaviors would most reduce someone's impact on the environment?

carpool instead of driving alone Carpooling to reduce automobile pollution is a great way humans can reduce their impact on the environment.

What do aerosols that contain chlorofluorocarbons (CFCs) do to the Earth's atmosphere?

cause the ozone hole to grow CFCs break ozone molecules apart, depleting atmospheric ozone and causing an increase in the size of the ozone hole.

skill 1.2 procedures and sources of information regarding the appropriate handling, use, disposal, care, and maintenance of chemicals, materials, specimens, and equipment

chemical waste should be disposed in properly labeled containers. waste should be separated based on their reactivity with other chemicals. Biological material should never be put in a well contained container with a secure lid to prevent leaking all biological waste should be disposed of in biological hazardous waste bags.

skill 1.2 procedures and sources of information regarding the appropriate handling, use, disposal, care, and maintenance of chemicals, materials, specimens, and equipment

chemicals should not be stored on bench tops or heat sources. They should be stored in groups based on their reactivity with one another and in protective storage cabinets. All containers in the lab must be labeled. Suspect and known carcinogens must be labeled as such and segregated within trays to contain leaks and spills.

Which type of graph or chart would be best used to show the breakdown of coat colors in a rabbit population?

circle graph Circle graphs are used to show parts of a whole. This is the best graph for this instance.

Fifth-grade students are working on an experiment and writing down their discoveries. Which of the following should the teacher be doing as the students work on the experiment?

coaching and guiding children as needed This is the best answer because the teacher is able to guide instruction on an as-needed basis.

Which of the following is an example of a positive feedback system?

contractions during labor and childbirth Contractions during labor and childbirth are an example of a positive feedback system, where the action causes a result further in the direction the system was already moving, as in, the process of labor advances.

What near-term effect might the dust and ash of a large volcanic eruption have on climate?

cooler summer temperatures Dust and ash might block sunlight causing temperatures to be cooler than normal.

results

data and observations gathered from the experiment. Drawings or graphs should be included to support information. Observations are objective whereas analysis and interpretation is subjective.

Evidence

data gathered in the course of scientific investigation, including measurements taken and observations made using the five senses

Which metric prefix indicates a factor of 10?

deca

metric system

decimal system of measurement based on certain physical standards and scaled on multiples of 10 learn the following basic units and prefixes

science

defined as a body of knowledge that is systematically derived from study, observations and experimentation. its goal is to identify and establish principles and theories which may be applied to solve problems.

Margin of Error

deviation or variation of a value from the correct or expected value to allow for error in equipment or calculations

Graphs used to display quantitative data:

dot plot stem-and-leaf plot (also called a stemplot) box-and-whisker plot histogram Students must learn how to interpret these graphs and other data gathered and communicate their knowledge. Written and oral reports should be a part of lessons so that students gain an understanding of how to share data. They also need to be able to analyze what other students or scientists have discovered and use this information in their own experiments. Using concept maps and flow charts to organize information can show students how seemingly distinct content relates to other content already covered.

Which of the following is an example of a natural phenomenon?

earthquake along a fault line A natural phenomenon is not affected by human interference or activity. An earthquake happens without human activity.

Scientific process unit on 240

effect of science module

balance

electronic balances are easier to use, but more expensive. An electronic balance should always be tare (returned to zero) before measuring and used on a flat surface. Substances should always be placed on a piece of paper to avoid spills and or damage to the instrument. Triple beam balances must be used on a level surface. there are screws located at the bottom of the balance to make any adjustments. start with the largest counterweight first and proceed toward the last notch that does not tip the balance. do the same with the next largest, etc until the pointer remains at zero. The total mass is the total of all the readings on the beams. again, use paper under the substance to protect the equipment.

Cara would like to research the effects of plants on students' self-reported stress levels. She places potted plants in student common areas for two weeks, taking surveys before and after. She then makes a graph of her findings. Which parts of the scientific method is Cara performing?

experimentation and data analysis Cara conducts an experiment (placing plants in common areas) and carries out data analysis (creating a graph of the results).

Variables

factors affecting the outcome of an experimental investigation the amount of water given to a plant might be the independent variable

Anton van Leeuwenhoek (1632-1723)

father of microscopy. in the 1650s leeuwenhoek began making tiny lenses that gave magnifications up to 300x. He was the first to see and describe bacteria, yeast plants, and the microscopic life found in water. over the years, light microscopes have advanced to produce greater clarity and magnification.

Which of the following is an example of qualitative data?

feather color Feather color is qualitative because it cannot be measured numerically. Instead, it is recorded as a category, such as "brown."

Of the following, which contributes the most to water pollution in streams?

fertilizers and pesticides Groundwater that drains into streams is most likely to be polluted by fertilizer and pesticide use. Runoff and drainage bring the pollutants to streams.

all science labs should contain the following items of safety equipment the following are requirements by law

fire blanket which is visible and accessible. Ground Fault Circuit Interrupters (GFCI) within two feet of water supplies. Emergency shower capable of providing continuous flow of water. signs designating room exits emergency eye wash station which can be activated by the foot or forearm eye protection for every student and a means of sanitizing equipment. emergency exhaust fans providing ventilation to the outside of the building. Master cut off switches for gas, electric, and compressed air. Switches must have permanently attached handles. Cut off switches must be clearly labeled. An ABC fire extinguisher. Storage cabinets for flammable materials. recommended but not required by law: chemical spill control kit, fume hood with a motor which is spark proof, protective laboratory aprons made of flame retardant material, signs which will alert people to potentially hazardous conditions. Containers for broken glassware, flammables, corrosives, and waste. Containers should be labeled.

whats next?

following the cracking of the genetic code biology has largely split between organismal biology consisting of ecology, ethology, systematics, paleontology, and evolutionary biology, developmental biology , and other disciplines related to molecular biology-including cell biology, biophysics, biochemistry, neuroscience, immunology, and many other overlapping subjects.

foresight

foresight is the anticipation that an event may occur under certain circumstances

the scientific method generally involves the following steps:

forming a hypothesis, choosing a method and design, conducting experimentation (collecting data), analyzing data, drawing a conclusion, and reporting the findings. depending on the hypothesis and data to be collected and analyzed, different types of scientific investigation may be used.

Malik set up a conversion: 3 gallons \times \frac{4 quarts}{1 gallon} \times \frac{2 pints}{1 quart} \times \frac{2 cups}{1 pint}×1gallon4quarts​×1quart2pints​×1pint2cups​ Which of the following conversions is he making?

gallons to cups The conversion begins with gallons and ends with cups. All of the other units will cancel out.

Greenhouse Gases

gases which, when present in elevated quantities in Earth's atmosphere, trap solar radiation and cause the planet to warm carbon dioxide

Which of the following is least likely to lead to error in the measurement of the volume of a liquid?

graduated cylinder A graduated cylinder has the most exact measurements of the tools listed. It will produce the least error.

graphing data

graphing utilizes numbers to demonstrate patterns. The patterns offer a visual representation, making it easier to draw conclusions.

Computer technology

has greatly improved the collection and interpretation of scientific data. Molecular findings have been enhanced through the use of computer images. Technology has revolutionized access to data via the internet and shared data bases. The manipulation of data is enhanced by sophisticated software capabilities. Computer engineering advances have produced such products as MRIs and CT scans in medicine. Laser technology has numerous applications with refining precision.

satellites

have improved our ability to communicate and transmit radio and television signals. Navigational abilities have been greatly improved through the use of satellite signals. Sonar uses sound waves bounce off the object and are used to assist in location. seismographs record vibrations in earth and allow us to measure earthquake activity.

Dimensional Analysis / Unit Analysis

he process of converting within or between systems by multiplying by factors of 1 in various forms

The primary function of a passive solar energy system is to convert solar radiation into:

heat for heating homes and buildings. Passive solar systems use energy from the sun to heat substances such as water, air, or concrete blocks. The heat is then used as a heat source in water heaters and for heating the insides of homes and buildings.

How are form and function related?

hey have a complementary relationship, with form allowing function and function enforcing the need for the specific form. This is the correct answer. Form and function complement each other, with form providing the mechanism for function, and function enforcing and requiring the specific form.

Greenhouse gases, released as a side-effect of modern urbanization and industrialization, have what effect on Earth's climate?

hey increase the amount of solar radiation in the atmosphere. Greenhouse gasses, such as carbon dioxide, increase the amount of solar radiation that is trapped in Earth's atmosphere and contributes to global warming.

Patrick likes to play horseshoes. He consistently tosses the horseshoes about one meter to the left of the stake. Which of the following accurately describes his results?

high precision, low accuracy The horseshoes are consistently close together, so they have high precision. The horseshoes are not close to the stake, so they have low accuracy.

bunsen burners

hot plates should be used whenever possible to avoid the risk of burns or fires. If bunsen burners are used, the following precautions should be followed: 1. know the location of fire extinguishers and safety blankets and train students. in their use. Long hair and long sleeves should be secured and out of the way. 2. turn on the gas and make a spark with a striker. The preferred method to light burners is to strikers rather than matches. 3. adjust the air valve at the bottom of the bunsen burner until the flame shows an inner cone. 4. adjust the flow of gas to the desired flame height by using the adjustment valve. 5. Do not touch the barrel of the burner (it is hot)

skill 2.3

how to gather, organize, display, and communicate data in a variety of ways (e.g , charts, tables, graphs, diagrams, written, reports, oral presentations

Terrance lives near a river and is concerned about the pollution caused by burning fossil fuels. Which alternative energy in his area would be the best solution for his concern?

hydroelectric energy Since Terrance lives near a river, water would be the best choice for an energy resource. The generation of hydroelectric energy is possible with flowing water.

Which order of steps correctly illustrates the process of risk assessment?

identify problems, predict an outcome, conduct research, interpret results, make decisions This is the correct order of risk assessment.

When is the best time to teach lab safety rules?

immediately before the students begin an experiment- Reminding students immediately before they begin using equipment is the best time because they can better remember and apply the specific safety rules to the specific equipment used during the experiment.

graphing

important skill to visually display collected data for analysis. The two types of graphs most commonly used are the line graph and the bar graph (histogram)

skill 1.2 procedures and sources of information regarding the appropriate handling, use, disposal, care, and maintenance of chemicals, materials, specimens, and equipment

in addition to the safety laws set forth by the government for equipment necessary to the lab. OSHA has helped to make environments safer by instituting signs that are bilingual. these signs use pictures rather than/in addition to words and feature eye catching colors. some of the best-known examples are exit, restrooms, and handicap accessible.

Louis Pasteur (1822-1895)

in the late 1800s, pasteur discovered the role of microorganisms in the cause of disease, pasteurization , and the rabies vaccine. Koch took his observations one step further by formulating that specific diseases were caused by specific pathogens.

Which is the most appropriate unit to measure the height of the average adult human?

inches Inches are of an appropriate scale to measure the height of a human because most human adults measure between 50-80 inches, which are whole numbers that are not too large nor too small. Numbers between 0-100 are easy to understand and conceptualize.

Which of the following is the best way to engage students from diverse cultural backgrounds in the practices of science?

incorporate science lessons that develop from the actual experiences of students in their culture Incorporating science lessons that tie to students' cultural experiences engages these students by providing connections between their world and scientific study, and shows that science is not only for the culture of the majority.

As humans burn more and more fossil fuels on Earth, the amount of carbon dioxide trapped in the atmosphere increases, causing the average temperature of the Earth to:

increase. Increased carbon dioxide in the atmosphere traps more solar energy, increasing the average temperature of the Earth.

Freshwater is a limited resource that is needed to sustain much of life on Earth. Which of the following reduces the availability of fresh drinking water for humans and animals?

increased crop irrigation As humans increase their use of freshwater to water crops, there is less available for other uses.

Of the following, which is thought to be the biggest contributor to the warming of the Earth's atmosphere since the 19th century?

increasing carbon emissions into the atmosphere Increasing carbon emissions is the dominant thought as to why Earth's atmosphere warmed since the 19th century due to human activities.

The change in arctic sea ice between 1980 and 2012 is most likely the result of which of the following?

increasing global temperature due to greenhouse gas emissions As greenhouse gas emissions continue to raise the global temperature, Arctic sea ice also continues to melt.

Which type of graph or chart would be best used to show the velocity of a moving vehicle at different points of a road trip?

ine graph Line graphs are used to show change over time. This is the best graph for this instance.

Observations

information gathered using the five senses smell, color

A pest control company would like to develop a home lawn spray for a new pest that has been eating the grass in local lawns. The company's chemists create a product, test it on sample lawns in laboratory settings, and record what happens. The company then puts the product out for mass production. Which of the following steps in the risk assessment process was skipped?

interpret results The company put the product out for production without interpreting the results of their tests first. This could lead to unexpected or ignored effects that could damage ecosystems.

centrifugation

involves spinning substances at a high speed more dense part of a solution will settle to the bottom of test tube, lighter material will stay on top. centrifugation is used to separate blood into blood cells and plasma with the heavier blood cells settling to the bottom.

controlled experiment

is a form of scientific investigation in which one variable, the independent or control variable is manipulated to reveal the effect on another variable, the dependent (experimental) variable, while all other variables in the system remain fixed. the control group is virtually identical to the testing the effects of bleach water on a growing plant, the plant receiving bleach be the control group. it is good practice to have several replicate samples for the experiment being performed, which allows for results to be averaged or obvious discrepancies to be discarded.

comparative data analysis

is a statistical form of investigation that allows the researcher to gain new or unexpected insight into data based primarily on graphic representation. Comparative data analysis, whether within the research of an individual project or a meta-analysis, allows the researcher to maximize the understanding of the particular data set, uncover underlying assumptions, and detect outliers and anomalies. Most comparative data analysis techniques are graphical in nature with a few quantitative techniques. the use of graphics to compare data allows the researcher to explore the data open-mindedly.

circle graph or pie chart

is an illustration that presents the data as parts of a whole. This is useful when the results are in the form of percentages.

data table

is an organized way to display data collected in labeled rows and columns.

classification

is grouping items according to thier similarities. It is important for students to realize relationships and similarity as well as differences to reach a reasonable conclusion in a lab experience.

Precision

is how close different measurements are to one another.

accuracy

is how close the measurements are to a true value. It is possible for a set of values to be precise but not accurate or vice versa. A common analogy used is a dartboard.

variability

is inherent in biology because living things are innately unique. For example, the individual weights of humans vary greatly from the mean weight of the population. Thus, when conducting experiments involving the study of living things, we must control for innate variability. Control groups are identical to the experimental group in every way with the exception of the variable being studied. Comparing the experimental group to the control group allows us to determine the effects of the manipulated variable in relation to statistical variability.

statistical variability

is the deviation of an individual in a population from the mean of the population.

Negligence

is the failure to exercise ordinary or reasonable care.

skill 3.8 demonstrates an understanding of how to communicate and defend the results of an inquiry based investigation

it is the responsibility of the scientists to share the knowledge they obtain through their research. After the conclusion is drawn, the final step is communication. in this age, much emphasis is put on the way and the method of communication. the conclusions must be communicated by clearly describing the information, using accurate data, visual presentation and other appropriate media such as a power point presentation. Examples of visual presentation are graphs (bar/line/pie), tables / charts, diagrams, and artwork. modern technology must be used whenever necessary. The method of communication must be suitable to the audience. written communication is as important is as important as oral communication. This is essential for submitting research papers to scientific journals, newspapers, other magazines etc.

which metric prefix indicates a factor of 1000?

kilo kilo- indicates a factor a 1000

Which of the following is the responsibility of the teacher with regard to the use of chemicals?

knowing the chemicals used in each laboratory experiment and reviewing the material safety data sheet for them The teacher is responsible for knowing the substances and reviewing the safety guidelines.

Calvin planted a tree that measured 0.5 meters tall. If he recorded the growth of the tree every month for two years, what would be the best way to display his findings, in order to visually compare the progression of growth over time?

line graph Recording the growth of a tree for two years shows a trend measured over a period of time. A line graph is the best visual representation to use to display this data.

You know that your height is 5 ft 3 in. A friend measures you three times and gets these results: 5 ft 10 in, 5 ft 9.5 in, and 5 ft 10.5 in. How can these measurements be explained?

low accuracy, high precision Accuracy is how close a value is to the true value. Precision is how close two measurements are to one another. The heights measured by your friend have low accuracy and high precision.

Patricia is measuring the volume of a chemical in the lab using a graduated cylinder. She takes three measurements at 40 mL, 35 mL, and 50 mL. She pours the chemical into a 50-mL beaker, and it reaches the 50-mL marking exactly. Which of the following descriptions of her data is likely correct?

low accuracy, low precision The values are far from the actual value, so they have low accuracy. The values measured are far apart, so they have low precision.

18th century

many fields of science like botany, zoology, and geology began to evolve as scientific disciplines in the modern sense.

meter

measure of length

gram

measure of mass

liter

measure of volume

Data

measurements and observations recorded during an experiment

When reading the volume of a liquid in a test tube, data measurements should always be taken from where?

meniscus The curve on the surface of the liquid is called the meniscus. This is where volumes of liquid should be measured.

Which is the most appropriate unit to measure length of the average football field?

meters A meter is close to a yard which is the actual unit for measuring a football field.

Density is measured by using the formula mass/volume. In addition to a scale, which of these tools would be helpful in finding the density of a regular-shaped, solid object?

metric ruler The density of an object is calculated by measuring both the mass and volume, and dividing the volume into the mass. The volume of a regular-shaped object is calculated by measuring the L x W x H of that object. This measurement is done with a metric ruler.

skill 3.1 the characteristics of various types of scientific investigations

most research in the scientific field is conducted using the scientific method to discover the answer to a scientific problem. The scientific method is the process of thinking through possible solutions to a problem and testing each possibility to find the best solution.

Natural Phenomena

natural events produced by natural forces which cause noticeable changes to the earth's surface tornadoes, tsunamis

Which of the following sources of energy is nonrenewable?

natural gas Natural gas is a fossil fuel; it is nonrenewable.

Which of the following is a nonrenewable resource?

natural gas Natural gas takes many years to replenish, and there is only a limited supply of natural gas on Earth.

Which of the following is not considered to be a renewable resource?

natural gas Renewable resources are those that are replenished more quickly than they are used up. Non-renewable resources are those that are used up more quickly than they are replenished, such as natural gas.

Which of the following scientists is particularly noted for his or her contribution to atomic theory?

niels bohr is known for his contributions to atomic theory (bohr model)

Which of the following best describes a resource that, once used, cannot be replaced or reused?

nonrenewable A nonrenewable resource is a resource that cannot be renewed, replaced, or reused.

Which of the following is not a renewable resource?

nuclear fuel Nuclear fuel is a nonrenewable resource. There is a finite amount of radioactive material to use.

skill 3.4 understands the roles that logical reasoning, verifiable evidence, prediction, and peer review play in the process of generating and evaluating scientific knowledge.

observations, however general they may seem, lead scientists to create a viable question and an educated guess (hypothesis) about what to expect. While scientists often have laboratories set up to study a specific thing, it is likely that along the way they will find an unexpected result. It is always important to be open minded and to look at all of the information. An open-minded approach to science provides room for more questioning, and, hence, more learning.

form a hypothesis

once the question is formulated, the experimenter can make an educated guess about the answer to the problem or question. this best guess is your hypothesis.

What is the most important use of a control group in an experimental investigation?

ontrol groups give a baseline to compare results to. Control groups allow scientists to compare the experimental results with a baseline expectation.

Which of the following human activities is least likely to alter the environment?

overwatering the lawn Overwatering a lawn can cause erosion, decrease water as a resource, and eventually decrease a number of organisms in that specific area. However, the overall negative impact is not as detrimental as the other answer choices.

Which of the following is not considered a greenhouse gas?

oxygen Oxygen is not a greenhouse gas. It does not significantly contribute to increasing global temperatures.

microbiology

pathogenic organisms must never be used for experimentation students should adhere to the following rules at all times when working microorganisms to avoid accidental contamination. 1. treat all microorganisms as if they were pathogenic 2. maintain sterile conditions at all times.

Suppose you are testing a hypothesis for a science fair project, and the first time you test it you get the results you were expecting. Which step should be taken next?

perform the experiment a few more times to see if the results are the same In order for results to become a scientific law or theory, the same results or pattern should be observed many times. The experiment should be performed again to see if the results are the same or have the same pattern.

Models

physical, mathematical, or visual representations of scientific phenomena a diagram of the eye

A student was given the kernels from an ear of seed corn that had been placed in a moist environment and allowed to sprout. The student sorted the kernels and found the percentage of kernels that had not changed at all, the percentage that had swollen but not sprouted, and the percentage that had sprouted. Which of the following types of graph is most the appropriate to use to present the findings?

pie graph A pie chart is useful for comparing parts of a whole, in this case, percentages.

Which of the following is the most appropriate unit for expressing the volume of an average glass of milk?

pint One pint is a volume of 2 cups and is best for expressing the volume of a glass of milk.

Alysha pours about 70 mL diluted base from the stock container into a beaker, then measures out 50 mL of this into her graduated cylinder. What should she do with the remainder of the diluted base in her beaker?

pour it into the liquid waste bottle Excess chemicals should be put in provided liquid waste bottles.

240 quizzes- A student measures the volume of 12.8 ml of liquid with a graduated cylinder, checking the measurement three times to obtain volumes of 13.2 ml, 13.2 ml, and 13.1 ml. The student's measurements are:

precise but not accurate. The student's measurements are precise, since the student obtained a close reading each time, but they are not accurate, since their average is not close to the correct volume. The student may have been measuring from the top of the meniscus.

240 quiz- scientific instruction

quiz 1

Which of the following is the best example of a science principle with themes and concepts that cut across all science disciplines?

rates of change The study of rates of change is a universal concept in science, applicable to all fields of science.

Casey is building a treehouse in his backyard. He works on it every day with all of his friends. Casey has little interest in science until Mrs. Baker teaches simple machines, and uses Casey's construction project as an example for how pulleys make lifting the building materials much easier. What process does Mrs. Baker use to encourage Casey's love for science?

real-world situations for application Research shows that if teachers want to engage their students in learning, they must first provide connections to their students' real-world. When students can understand the real-world connection, they are more interested in the content. In addition to this connection, hooking the content to the interests of the students builds a love for that content.

A scientist is performing an experiment to determine the conductivity of a specific substance. Which of the following actions would increase the reliability of the results?

recording the results of repeated experiments To increase reliability, at least three trials for every experiment should be completed and the data recorded.

Which of the following would be the most effective strategy to reduce greenhouse gases?

reducing the use of fossil fuels The burning of fossil fuels releases carbon dioxide into the atmosphere. Carbon dioxide is a greenhouse gas.

If a piece of laboratory equipment breaks during an activity, which of the following courses of action would provide the most benefit to the students?

remove the broken equipment from the students' lab area and replace it with functioning equipment. This course of action allows the students to continue with the activity in the safest manner.

Biomass

renewable resource made from plant and animal matter

Robert Hooke (1635-1703)

renowned inventor, a natural philosopher, astronomer, experimenter and a cell biologist. He deserves more recognition than he received, but he is remembered mainly for hooke's law, an equation describing elasticity that is still used today.He was a scientist that was then called a virtuso- able to contribute findings of major importance in any field of science. Hooke published micrographia in 1665. Hooke devised the compound microscope and illumination system, one of the best such microscopes of his time , and used it in his demonstrations at the royal society's meetings. with it he observed organisms as diverse as insects, sponges, byrozoans, foraminifera, observations, illustrated with magnificent drawings.

observe and record the data

reporting of the data should state specifics of how the measurements were calculated. A graduated cylinder needs to be read with proper procedures. As experimenters, technique must be part of the instructional process so as to give validity to the data.

Renewable Resources

resources which replenish at the same (or faster) rate than the rate at which they are used wind energy, solar energy, hydroelectric power

Non-Renewable Resources

resources which will be depleted faster than they can be replenished natural gas, petroleum

responsibility of teachers to provide a safe environment for their students. Proper supervision reduces the risk of injury and a teacher should never leave a class for any reason without providing alternate supervision.

safety procedures should be a part of the science curriculum and a well managed classroom is important to avoid potential lawsuits.

A scientist wants to show the correlation between the genre and the number of songs downloaded from the internet. Which type of graph would be best suited for this?

scatter plot A scatter plot is used to show correlation and relationships between variables.

which of the following is true is science?

science is open to change as new information is discovered

why does scientists use the metric system ?

science uses the metric system as it is accepted worldwide and allows easier comparison among experiments done by scientists around the world

Scientific Knowledge

scientific fact discovered using the scientific method

Example 3: Convert 3 gallons to milliliters, using the conversions listed below.

see screen shot- practice solving problem using the conversion chart- learn and memorize conversions!

Example 1 (English to English): 1 pound (lb.) = 16 ounces (oz.) How many pounds are there in 40 oz?

see screen shots- practice solving problem

Example 2 (English to metric): There are 4.18 Joules in 1 calorie. How many Joules are in 2001 kilocalories?

see screen shots- practice solving problem To solve using dimensional analysis, line up as many true conversion factors as needed. Anything shown once in the top and once in the bottom can cross out.

competency 2.0 understanding the correct use of tools, materials, equipment, and technologies skill 2.1

select and safely use appropriate tools, technologies, materials, and equipment needed for instructional activities.

conclusion

should explain why the results of the experiment either proved or disproved the hypothesis.

line graph

shown below, shows how the responding variable changes in response to the manipulated variable and/or displays trends over time. see screenshot

Input

something put into a system that causes change temperature changes in environment

Which of the following diseases can be effectively treated with an antibiotic?

strep throat Strep throat is caused by the streptococcal bacteria, which can be killed with an antibiotic.

Which of the following are appropriate lab safety standards? Select all answers that apply.

students should wear safety goggles when working with a flame. Safety goggles are recommended whenever students work in the lab, especially when working with heat, glassware, or chemicals. Regular prescription glasses and sunglasses are not sufficient. A first aid kit should be kept in the classroom. A first aid kit should be available in the classroom to treat minor injuries. eye wash should be for about 15-20 mins students should never clean up a spill or accident without the teachers supervision

differentiating causes and effects

students, with appropriate direction from you (the teacher), should be able to review the data, summarize, and form a logical argument about the cause - and effect relationships. It is important to differentiate between causes and effects and determine when causality is uncertain.

Chlorofluorocarbons (CFCs)

substances used for insulation, aerosols, and refrigeration; they break apart ozone molecules

skill 3.3 the historical development of science and the contributions that diverse cultures and individuals of both genders have made to scientific knowledge.

the history of biology traces man's understanding of the living world from the earliest recorded history to modern times. Though the concept of biology as a field of science arose only in the 19th century, the origin of biological sciences could be traced back to ancient greeks (galen and aristotle). during the renaissance and age of discovery, renewed interest in the rapidly increasing number of known organisms generated lot of interest in biology.

Function

the job or purpose of an object or part of a system the purpose of a bird's wings (flight)

Feedback Loop (in Systems)

the part of a system in which some (or all) of the system's output is used as input for future operations body temperature regulation - the body temperature is achieved and then measured for future changes needed

Risk Assessment

the process by which scientists analyze potential risks and benefits before conducting scientific investigations and experiments

peer review

the process of fact-checking by other experts in the same field; ensures the quality of published work

purpose

the reason for which something is done or created or for which something exists.

In the 20th century

the rediscovery of mendel's work led to the rapid development of genetics by Thomas Hunt Morgan and his students.

skill 3.2 how to design, conduct, and communicate the results of a variety of scientific investigations

the scientific method is the basic process behind science. It involves several steps beginning with hypothesis formulation and working through to the conclusion.

Form

the shape of an object or part of a system the shape of a bird's wings

Greenhouse Effect

the trapping of the sun's heat in the atmosphere due to the increased presence of gases in the atmosphere; light is allowed to pass through, but heat is trapped, similar to the glass walls of a greenhouse

Meters (m)

the unit for distance in the metric system The pool was 6 m deep.

During part of a lab activity, students need to let a solution evaporate to see if any solutes are left behind. Which of the following tools would be most appropriate for this purpose?

the watch glass would be the most appropriate tool for this, since it is shallow and allows for a greater surface area of the solution to be exposed. This would allow the solution to evaporate more quickly.

abstract

theoretical; not concrete; nonrepresentational

Which of the following is a widely-accepted explanation that is supported by observational evidence and experimental confirmation?

theory A theory is a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.

graduated cylinder

these are used for precise measurements. they should always be placed on a flat surface. the surface of the liquid will form a meniscus (lens-shaped curve). The measurement is read at the bottom of this curve.

Which one of the following tools would be most appropriate to measure the velocity and acceleration of a toy car in a lab activity?

ticker timer The ticker timer can be used to measure both time and distance, providing velocity and acceleration. This device uses carbon paper and a timer to mark dots on a piece of tape drawn through the apparatus at a set frequency. One end can be attached to the car and the distance between the dots can be measured and used to calculate velocity and acceleration.

Which of the following is not a reason to perform peer review on scientific research?

to change the data so that it proves the hypothesis Data should never be changed to prove a hypothesis. Peer review is to ensure that the researchers did not make errors, whether accidentally or on purpose.

A seismograph is used for which of the following?

to determine the epicenter of earthquakes Seismographs are used to determine the location of the epicenter of an earthquake.

conducting a test

to make a test fair, data from an experiment must have a variable or any condition that can be changed such as temperature or mass. A good test will try to manipulate as few variables as possible so as to see which variable is responsible for the result. This requires a control.

An echo sounder is used for which of the following?

to map the ocean floor Echo sounders are used in mapping the ocean floor. Depth and ocean floor structures can be detected by measuring the time it takes an echo to return to the sounder.

skill 3.5 understands principles of scientific ethics

to understand scientific ethics, we need to have a clear understanding of ethics. Ethics is defined as a system of public, general rules for guiding human conduct (gert, 1998). The rules are general in that they are supposed to all people at all times and they are public in that they are not secret codes or practices. scientists are expected to show good conduct in their scientific pursuits. Conduct here refers to all aspects of scientific activity including experimentation, testing, education ,data evaluation, data analysis, data storing, peer review, government funding, the staff ,etc.

Mr. Reynolds is working through a unit on healthy lifestyles. He wants to incorporate the leading cause of preventable death in the United States. Which of the following causes of death should Mr. Reynolds use?

tobacco use Tobacco use is the leading cause of preventable death in America.

Single-Variable Research

type of non-experimental investigation in which the researcher makes observations before and after the application of a treatment or question hidden-camera shows in which a magician tries the same trick with different groups of people

flash cards: Quasi- Experimental Research

type of non-experimental investigation in which the researcher studies the effects of an independent variable, but chooses experimental groups rather than assigning them randomly a nutritionist starts a nutrition education program at one nursing home and not at another one, then compares the health of the residents at each nursing home afterward

Essential concepts that must be understood in the subject of measurement are:

types of measurement available units for the English customary system and the metric system which unit will be most appropriate for a particular task conversion from one unit to another the margin of error for a given measurement tool While the unit fractions used to convert units within a measurement system can be relied upon completely (12 inches really is exactly 1 foot, so both 12 in/ 1 ft and 1 ft/12 in are exactly equal to 1), unit fractions for use in converting between measurement systems can be seen as slightly inaccurate. For example, 2.54 cm is "equal" to 1 in., but due to slight errors in measurement tools, this conversion may be slightly inaccurate.

UVB Rays

ultraviolet rays that can damage cells; can cause skin cancer and premature skin aging

skill 3.7 demonstrates an understanding of potential sources of error in inquiry based investigation.

unavoidable experimental error is the random error inherent in scientific experiments regardless of the methods used. One source of unavoidable error is measurement and the use of measurement devices. Using measurement devices is an imprecise process because it is often impossible to accurately read measurements. For example, when using a ruler to measure the length of an object, if the length falls between markings on the ruler, we must estimate the true value. Another source of unavoidable error is the randomness of population sampling and the behavior of any random variable. For example, when sampling a population we cannot guarantee that our sample is completely representative of the larger population. in addition, because we cannot constantly monitor the behavior of a random variable, any observations necessarily contain some level of unavoidable error.

competency 3.0

understanding the process of scientific inquiry and the history and nature of science

One way to convert between units is to use a proportion, a pair of equal fractions. One fraction is a known conversion and the other is the given and the goal in the problem.

unit 1/ unit 2 =unit 1/ unit 2 To do a metric to metric conversion, you should be familiar with the multiples of 10 that correspond to each prefix (ex: 1 kilometer = 1000 meters). For all other types of conversions, the conversion rate will most likely be given to you.

electrophoresis

uses electrical charges of molecules to separate them according to their size . The molecules such as DNA or proteins are pulled through a gel towards either the positive end of the gel box (if the material has a negative charge) or the negative end of the gel box (if the material has a positive charge).

spectrophotometry

uses percent light absorbance to measure a color change, thus giving qualitative data a quantitative value.

Chromatography

uses the principles of capillary action to separate substances such as plant pigments. Molecules of a larger size will move slower up the paper, whereas smaller molecules will move more quickly producing lines of pigments.

Which of the following examples illustrates a student using critical thinking skills and information learned in science class and applying them to their daily life?

using a simple machine to reduce effort when moving boxes Applying knowledge to a new situation and understanding cause and effect are indications of critical thinking.

Natural resources are resources naturally occurring on Earth that are necessary or useful to humans. Natural resources include:

water, wood, and minerals. Natural resources occur naturally; they are not man-made materials. Water, wood, and minerals are all found naturally on Earth.

example of scientific ethics

we can look at natural phenomena like rain. Rain in the normal sense is extremely useful to us and it is absolutely important that there is a water cycle. When rain gets polluted with acid, it becomes acid rain. here lies the ethical issue of releasing all these pollutants into the atmosphere. Should the scientists communicate the whole truth about acid rain or withhold some information because it may alarm the public? There are many issues like this. Whatever may be the case, scientists are expected to be honest and forthright with the public.

Correlational Research

ype of non-experimental investigation in which the researcher may study two variables, but does not control the rest of the conditions of the study a teacher who gives students one questionnaire about how many in-class activities they participate in and one about how engaged they feel in class