Chapter 1 powerpoint review

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

Scientists continue to monitor the amount of CFCs in the atmosphere and the annual changes in the amount of ozone in the stratosphere. Scientists continue to conduct research to find replacement chemicals for CFCs that are now banned. What type of research is this?

applied research

_________ ___________ is research undertaken to solve a specific problem.

applied research

CFCs were first detected ______________ in the 1970s, and the concentrations continued to increase through the 1990s.

atmosphere

Chemistry explains events on the ________ level (submicroscopic) that cause macroscopic observations.

atomic

What was the dependent variable?

bacteria growth

Scientists Molina and Rowland were motivated by curiosity when they conducted their research on CFCs and their interactions with ozone. No environmental evidence at the time indicated that there was a correlation to their model in the stratosphere. Discovery of ozone, they were just trying to _______ _________

gain knowledge

A ___________ is never proven, only supported or discarded.

hypothesis

A ________________ is a tentative explanation for what has been observed

hypothesis

The steps in a scientific method are repeated until a ____________ is supported or discarded.

hypothesis

what is never proven, only supported or discarded

hypothesis

What is a measure of mass and the force of gravity on an object.

Weight

In the 1920's, large-scale production of refrigerators began, which used __________ as coolant.

ammonia

what research is to solve a problem

applied

An ______________ variable is the variable you plan to change.

independent

An observation is the act of gathering what?

information

Pros of models is that

it simplifies hard things and they allow you to predict

what are statements of facts such as speed of light

law

If your hypothesis is right than you can come up with a _________ or _______

law or theory

The _____________ ___________ is a systematic approach used in scientific study, whether it is chemistry, physics, biology, or another science.

scientific method

Scientists hypothesized that CFCs, although stable, break down in the stratosphere due to interactions with__________ ___________ from the Sun, and that the chlorine produced by this interaction would break down ozone

ultraviolet radiation

A ______________ is a quantity or condition that can have more than one value.

variable

mixtures have a _________ composition therefore __________ properties - air, sugar water

variable and variable

•All substances that are classified as CFCs are: - - -

-Man-made (they do not occur naturally) -Nontoxic -Stable (they do not readily react with other substances)

A basic understanding of chemistry is central to all sciences—biology, physics, Earth science, ecology, and others. Chemistry is traditionally broken into branches that focus on specific areas such as:

-Organic chemistry -Inorganic chemistry -Physical chemistry -Analytical chemistry -Biochemistry -Environmental chemistry ‒Industrial chemistry ‒Polymer chemistry ‒Theoretical chemistry ‒Thermochemistry

Ozone has interested and been studied by scientists since the late ____________

1800's

In the mid-1980s, Scientists detected thin areas in the ozone layer over ____________.

Antarctica

Scientists observed that there were ________ in the atmosphere and that their levels were increasing.

CFCs

•What are chlorofluorocarbons and how do they get into the atmosphere?

Chlorofluorocarbons are a substance that consists of chlorine, fluorine and carbon. They are used for refrigerators and AC units, for use in plastic foams and as propellants in spray cans. They are sent into the atmosphere this way

________ __________ is research to gain knowledge for the sake of knowledge itself.

Pure research

what research is to gain knowledge (discovery of knowledge)

Pure research

_______________ data is obtained through observations that describe color, smell, shape, or some other physical characteristic that is related to the five senses.

Qualitative

what is a measurement that reflects the amount of matter.

Mass

_________________ data is obtained from numerical observations that describe how much, how little, how big or how fast

Quantitative

what is a substance in the atmosphere made up of oxygen.

Ozone

•How does ozone form and why is it important?

Ozone, in the stratosphere, is formed when oxygen gas (O2) is exposed to ultraviolet radiation. Ozone absorbs most ultraviolet radiation and protects living organisms.

What radiation damages living organisms

Ultraviolet

In an attempt to find safer coolant, chemist, ____________. synthesized the first chlorofluorocarbons in 1928.

Thomas Midgley, Jr

___________ discoveries occur when scientists obtain results that are far different from what they expected. -Example: Alexander Fleming's discovery of Penicillin. -Is to solve a problem, specific

chance

•A Chlorofluorocarbon (CFC) is a substance that consists of __________, _________, __________.

chlorine, fluorine and carbon.

A _______________ is a judgment based on the information obtained from the experiment.

conclusion

A _____________ is a standard for comparison in the experiment.

control

As verb you __________ all possible other influences of growth such as pH, gases, sunlight, UV rays, food, etc.

control

The group receiving the placebo is the __________ group.

control

___________ can also be a sample of bacteria just to see what it does naturally

control

Because of being nontoxic and very stable, they seemed to be ideal ______________ for refrigerators and AC units, for use in plastic foams and as propellants in spray cans.

coolants

The _____________ variable is the variable that changes in value in response to a change in the independent variable.

dependent

During clinical drug trials, physicians will use a _____________ study. They use two statistically identical groups of patients. One will receive the drug and one will receive a placebo. Neither patient or physician will know which group receives the drug.

double-blind

Hypothesis is a testable explanation, ____________ guess

educated

Ozone forms over the __________, where the rays of sunlight are the strongest and then flows towards the poles, thus, making it a convenient marker to follow the flow of air in the stratosphere.

equator

Observations make questions with __________ knowledge

existing

An ________________ is a set of controlled observations that test the hypothesis.

experiment

Much of matter and its behavior is ____________, meaning that it can be observed without a microscope.

macroscopic

Models will be used to show the ____________ events that occur and they are only as good as what it can ___________

macroscopic and predict

If your hypothesis is wrong, then you should ________________________

make a new hypothesis and test that

Weight can change from place to place, but _______ is constant.

mass

What is anything that has mass and takes up space?

matter

___________ are a mixture of multiple compounds

mixtures

A __________ is a verbal, visual, or mathematical explanation of experimental data.

model

Ozone, in the stratosphere, is formed when __________ is exposed to ultraviolet radiation.

oxygen gas (O2)

Earth's atmosphere contains a layer of _________ that absorbs most ultraviolet radiation and protects living organisms.

ozone

research showed that CFCs and a few other chemicals react with ozone. Many nations agreed in 1987 to the Montreal Protocol, to __________ _______ CFC use.

phase out

Theories are successful if they can be used to make ____________ that are true

predictions

what are all elements and compounds

pure substances

•Chemists solve many _______ problems we face today such as: -Ozone depletion -Finding cures for diseases -Reducing automobile pollution

real

Experiment can either be _________ or __________

right or wrong

A ___________ ______ is a relationship in nature that is supported by many experiments, and no exceptions to these relationships are found.

scientific law

It is an organized process used by scientists to do research, and provides methods for scientists to verify the work of others.

scientific method

Systematic, methodical, steps you have to follow. No question means cant do it. What is that?

scientific method

This layer blocks UV radiation from living organisms and with out it we would all have to much UV radiation

stratosphere

Earth's atmosphere consists of several layers. The protective ozone layer is located in the ___________

stratosphere.

The structure, composition, and behavior of all matter can be described on the _____________ (atomic) level.

submicroscopic

A ____________, also known as a chemical, is matter that has a definite composition.

substance

also known as a chemical, is matter that has a definite composition.

substance

What was the independent variable?

temperature

If you were trying to determine if temperature affects bacterial growth, you would expose different petri dishes of the same bacteria to different ___________

temperatures.

If you were trying to determine if temperature affects bacterial growth, you would expose different petri dishes of the same bacteria to different temperatures. Hypothesis - Experiment - Dependent - Independent -

the growth rate of bacteria is controlled by the temp measure amount of bacteria at diff. temp's is always y is always x and can be changed

A _________ states a broad principle of nature that has been supported over time by repeated testing and are successful if they can be used to make predictions that are true.

theory

A ___________ is an explanation that has been repeatedly supported by many experiments.

theory

A ___________ states a broad principle of nature that has been supported over time by repeated testing.

theory

scientific _________ explain why things happen and are much more useful, theories are also predictive

theory

Cons of models is that

they sometimes make things too simple, so not as precise as the real thing and to general

pure substances have _________ composition therefore _________ properties - H20, CO2, ozone

thick and thick

North and South poles have a _______ ________ not a hole Healthy is 300 Hole is 100

thin layer


Ensembles d'études connexes

Boiler Operation Principles Chp. 1

View Set

CLEP Exam - Information Systems & Computer Applications

View Set

Midterm (Chapters: 1,3,4,18,5,6,7,8,9,10,11,12,13,14,15)

View Set