Chapter 1 powerpoint review
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
