Scientific Inquiry

Law of conservation of matter: The law would also apply to chemical reactions in another galaxy.

Characteristic of a scientific law: intended to be universal

Law of conservation of matter: The law only describes amounts of matter not changing.

Characteristic of a scientific law: statement about something specific observed in nature

Law of conservation of matter: Lavoisier devised a means of comparing all the matter before and after the chemical reaction.

Characteristic of a scientific law: tested by experiment

T/F: New evidence that explains how the plates move was key to helping scientists accept the theory.

False

Droughts cause significant socioeconomic damage each year. A group of scientists observes the frequency of droughts in a certain region to try to determine processes that can help predict droughts.

Primary field(s) of physical science: Earth science

A group of scientists uses lasers to produce light waves that are then sent through the atmosphere. The light waves that scatter off air molecules are collected and analyzed. The information gathered is used to determine the distribution of air pollutants in the atmosphere.

Primary field(s) of physical science: Earth science and physics

A team of scientists works on designing a new substance that could improve the taste of sugar-free food products.

Primary field(s) of physical science: chemistry

Metals that leak from mine waste sites pollute groundwater and are dangerous to the environment. A group of scientists investigates the possibility of using certain chemicals to reduce the leakage of metals from mine waste sites.

Primary field(s) of physical science: chemistry and Earth science

Scientists analyze the forces involved in a serious vehicle collision.

Primary field(s) of physical science: physics

Scientists develop a solar cell made with large organic molecules that can undergo chemical changes and produce electricity from sunlight.

Primary field(s) of physical science: physics and chemistry

law

a concise statement that is supported by scientific evidence and repeated experiments and describes a widespread pattern in nature

In the previous experiment, the wire's length is an example of

a dependent variable. The wire's length changes as its temperature is changed. Therefore, the wire's length is the dependent variable.

theory

a statement that explains a wide range of observations and that is supported by a large body of scientific evidence

hypothesis

a testable statement about how something in nature works

When scientists want to determine the hardness of minerals, they use a test called the Mohs test. An experimenter trying to identify a mineral will scratch the surface with a set of tools of various hardness, and then analyze the results against charts.

a) controlled experiment A controlled experiment means that the variables are controlled by the scientist, in this case the mineralogist, who knows what to test and what variables to manipulate to answer the question.

A group of students sprinkle salt onto one of two burning candles and record the color of the two flames. a) controlled experiment b) observational study

a) controlled experiment The students are choosing the variable, in this case salt, meaning they can manipulate variables

The moon is made entirely of cheese. a) falsifiable b) not falsifiable

a) falsifiable

The third planet around the star Sirius has no moon. a) falsifiable b) not falsifiable

a) falsifiable

Galileo, a 16th-17th century astronomer and mathematician, questioned Aristotle's claim that heavy objects fall faster than lighter objects. He asked what would happen if the two objects were tied together. If Aristotle was right, the combined objects should be heavier and fall even faster. But the lighter object should also slow the heavier one, so that they would fall slower. Because both cannot be true, Galileo concluded that weight could not affect speed of fall. He confirmed this thought experiment by doing real experiments on falling objects and objects rolling down inclines. This type of reasoning about what seems likely to happen, followed by experiments to check predictions is BEST described as formulating and testing a a) hypothesis b) theory c) law

a) hypothesis A hypothesis is a tentative statement, assumed true for the purpose of further testing.

The method they use __________ involves proposing a hypothesis and then testing it. a) often b) always c) never

a) often

atoms

all living and non-living things are made of extremely small particles

In general, metal wires expand when they are heated. To test this, you heat a piece of wire and then measure how much the wire's length changed as a result of the temperature change. In this experiment, the wire's temperature is

an independent variable. Since you change the temperature in order to observe the effect on the wire's length, the temperature is the independent variable.

Which of the following is a primary investigation in Earth science? a) how magnetism can be used to image the body b) the composition of Earth's interior c) animal and plant life on an island in the Pacific Ocean d) the formation of mountain ranges, both above and under the ocean

b and c

Which of these is the correct analogy? a) A concrete foundation is to a house as a theory is to a law. b) A concrete foundation is to a house as a law is to a theory.

b) A concrete foundation is to a house as a law is to a theory. Theories are built on laws, not the reverse.

A theory __________ be fully proved true by testing it enough. a) can b) cannot

b) cannot No theory can be fully proved, because it is impossible to test every single occurrence of what it describes.

When the evidence convincingly shows a prediction of a theory to be untrue, the theory is most likely to be __________. a) discarded b) modified

b) modified

Invisible undetectable space aliens have been visiting Earth for centuries. a) falsifiable b) not falsifiable

b) not falsifiable

A student records the rising and setting times of the moon each day for a month. a) controlled experiment b) observational study

b) observational study This is an observational study, since the student has no control over the rising and setting of the moon.

Scientists at a volcano observatory continuously monitor the ground movements and volcanic gas chemistry between and during eruptions. a) controlled experiment b) observational study

b) observational study Variables in observational studies are controlled by the forces of nature, in this case the movement of magma and the Earth's crust.

The English physicist and mathematician Isaac Newton was born within about a year of Galileo's death. Newton succeeded in explaining a great many force and motion phenomena. Combined with his law of universal gravitation, Newton's laws of motion explain why the motion of falling objects does not depend on their mass and why the planets move in the ways Kepler had observed. Which term best describes the explanation Newton constructed? a) hypothesis b) theory c) law d) guess

b) theory What Newton constructed explained, not merely described, a wide group of phenomena. It has strong support because plenty of data was already available. This made it a theory rather than a hypothesis or a law.

What caused scientists to accept the theory of plate tectonics when they didn't accept Wegener's idea of continental drift? a) Evidence for continental drift does not support the theory of plate tectonics. b) Many scientists confirmed Wegener's observations, but only a few scientists confirmed the observations that led to the theory of plate tectonics. c) Plate tectonics provides a mechanism for plate motions that is supported by evidence. d) Wegener was not able to experiment to test his idea, but modern scientists have done experiments on the plates.

c) Plate tectonics provides a mechanism for plate motions that is supported by evidence. New evidence that explains how the plates move was key to helping scientists accept the theory.

Which of these BEST describes a scientific theory? a) a sudden understanding, such as when seeing an apple fall b) a law that has been tested over and over c) a well-tested explanation d) a tentative assumption e) a guess about why and how things happen

c) a well-tested explanation

he system of Ptolemy was an ancient description of the motion of the sun and other objects across the sky in terms of Earth as the center of the universe. In the Ptolemaic system, it was assumed that each object in the sky moves on its own imaginary sphere. The system of Ptolemy fits the description of a a) model b) theory c) both

c) both Using evidence that supports theories, scientist often create models to explain and simplify complex concepts.

Kepler, a 16th-17th century astronomer, analyzed astronomical data that his mentor, Tycho Brahe, had collected. He found three rules about how the planets orbit the sun that were always followed according to all the data he had. But he could not explain why the planets obeyed these rules. Each of the rules that Kepler discovered about the motion of the planets, without an explanation as to why the planets moved as they did, is BEST described as a a) hypothesis b) theory c) law

c) law The rules, known as Kepler's laws, describe rather than explain planetary motion, and are very narrowly focused on just planetary motion, not a very wide range of phenomena—which are earmarks of a law.

Which of the following would NOT be a primary investigation in physics? a) what keeps a bicycle from falling over b) why you can skate across ice c) what reactions occur that cause wood to burn in a fireplace d) how rainbows form

c) what reactions occur that cause wood to burn in a fireplace Wood burning involves chemical reactions with oxygen, which can be explained using chemistry.

The picture of the solar system is an example of a __________ model.

conceptual

You heard somewhere that salty water boils faster than pure water. You decide to do a scientific investigation to determine whether this is true. You get three identical pots. You put 4 cups of pure water in the first pot. In the second pot, you put 4 cups of water with 2 tablespoons of salt added. In the third pot, you put 4 cups of water with 4 tablespoons of salt added. Next, you heat all three pots at the same level of heat and measure how long it takes the water in each pot to boil. This is an example of a(n) __________ experiment.

controlled This is a controlled experiment, because you change one quantity (percentage of salt in water) and observe what happens to another quantity (time to boil).

Which of these best fits the description of a scientific law? a)Noticing that an apple falling from a tree speeds up as it falls. b) An authorization by Congress to spend money on scientific research. c) A proposed idea to test whether cold water sinks when added to warmer water. d) A statement based on many experiments that energy is never created or destroyed e) The statement, "Nature hates a vacuum."

d) A statement based on many experiments that energy is never created or destroyed A law is a concise statement based on many experiments or observations.

Which of these is a property that a falsifiable statement MUST have? a) It is untrue. b) It has been proved false. c) All attempts to prove it false fail. d) It is capable of being shown untrue.

d) It is capable of being shown untrue. A statement is falsifiable if there is some conceivable test with a result to check for that would show it untrue if the result is found.

Which of these is true of a hypothesis? a) It has been proved true. b) It seems very unlikely to be true. c) No evidence can prove it untrue. d) It remains to be tested.

d) It remains to be tested.

Which of these best summarizes the central idea of the big bang theory? a) The universe expanded from a tiny region but is now falling together. b) The universe has always existed and has remained essentially the same. c) The stars and planets were similar to those at present but were packed into a very small space. d) The universe began as a tiny region of space and changed as it expanded.

d) The universe began as a tiny region of space and changed as it expanded. According to the big bang theory, the universe began as a tiny, very high-density, high-temperature point.

The ancient Greek philosopher Aristotle proposed that a rock falls because it is seeking to return to its "natural place," namely the ground. What is the best reason why Aristotle's proposal would not be considered to be a scientific hypothesis? a) There is no way to prove it is true. b) The ground is not the rock's natural place. c) It does not describe the rock's motion. d) There is no way to prove it is untrue.

d) There is no way to prove it is untrue. it is not falsifiable, cannot be tested, and is not useful as a hypothesis, or even meaningful.

All of the following are studied by physical science EXCEPT __________? a) how lightning bolts form b) an explosion of a distant star c) an earthquake happening in the Pacific Ocean d) the feeding patterns of whales e) the development of sugar substitutes that do not alter food taste

d) the feeding patterns of whales Whales are living organisms, and so they fall within the realm of biological science

The time needed for the water in each pot to boil depends on several factors, such as the amount of liquid you use, the level of heat you use, and the size and composition of the pots you use. In this experiment, these are examples of variables. In this experiment, the salinity of water is a(n) __________ variable.

independent The salinity of water is an independent variable.

A theory and a law are also different because a __________ is about a specific behavior in nature, rather than being about many different phenomena.

law A law rather than a theory is about some very specific behavior in nature.

A theory and a law are different because the _________ merely describes what happens, rather than how or why things happen.

law Laws tell us what will occur based on research with large amounts of data collected over a long period of time.

Newton's second law of motion, which explains the relationship between force, mass, and acceleration, F = ma, is an example of a __________ model.

mathematical

molecules

particles containing more than one atom

A group of scientists studies the nature of earthquakes by passing mechanical waves through various materials in the lab. The scientists are using a __________ model.

physical

dependent variable

the one that changes because of the independent variable.

independent variable

the one that is being changed by the experimenter; however, it can also change on its own, as is the case with time.

earth science

the study of Earth and other plants, including their physical structures, materials, and processess

chemestry

the study of atoms and molecules, their structures, and their interactions to form substances

physics

the study of forces and energy