CMAC Chapter 1 Questions with
Complete Solutions
Explain why the study of chemistry should be important to everyone. (1.1) - ANSWER-
Chemistry is the study of matter and everything and everyone is made of matter.
Define substance and give two examples of things that are substances. (1.1) -
ANSWER-A substance, which is also known as a chemical, is matter that has a definite
composition. Possible examples: table salt and table sugar
Describe how the ozone layer forms and why it is important. (1.1) - ANSWER-When
oxygen gas (0²) is exposed to ultraviolet radiation in the upper regions of the
stratosphere, the molecule breaks apart. The individual oxygen particles (O) combine
with other oxygen gas molecules to form ozone (O³). Ozone is important because it
forms a protective layer in the atmosphere that protects living organisms from harmful
radiation.
Explain why chlorofluorocarbons were developed and how they are used. (1.1) -
ANSWER-Chlorofluorocarbons were developed as a safe alternative to ammonia, a
common refrigerant. Chlorofluorocarbons are used as refrigerants, in foams, and as
propellants in spray cans.
Explain If cells have the ability to repair themselves after exposure to UVB, why are the
increasing levels of UVB in the atmosphere concerning scientists? (1.1) - ANSWER-
Cells have some ability to repair themselves, but some scientists believe that cells have
a limit in the amount of UVB exposure that can be tolerated.
Explain why the concentration of CFCs increased in the atmosphere. (1.1) - ANSWER-
The use of CFCs continued to increase.
Evaluate why it was important for Dobson's data to be confirmed by satellite photos.
(1.1) - ANSWER-All scientific hypotheses, tests, experiments, and data must be
independently confirmed to make them valid.
Good scientific models can be tested and used to make predictions. What did Molina
and Rowland's model of the interactions of CFCs and ozone in the atmosphere predict
would happen to the amount of ozone in the stratosphere as the level of CFCs
increased? - ANSWER-Their models predicted that as CFC concentrations increased,
ozone levels would decrease.
, Name three technological products that have improved our lives or the world around us.
- ANSWER-Possible answers: computer, internal combustion engine, and vaccinations.
Compare and contrast pure research and applied research. - ANSWER-Pure research
is done for the sake of knowledge. Applied research is done to solve a specific problem.
Is technology a product of pure research or applied research? Explain. - ANSWER-
Technology can be the product of either one. It can be a product of pure research when
scientists realize their discovery has a practical application. It can also be a product of
applied research when scientists perform research to solve a particular problem.
Wear goggles and an apron in the lab even if you are only an observer. Why? -
ANSWER-Harmful substances can get in your eyes and on your clothing if you are
performing an experiment or just watching it being performed.
Do not return unused chemicals to the stock bottle. Why? - ANSWER-The chemicals
might be contaminated and you do not want to contaminate the stock bottle.
Do not wear contact lenses in the laboratory. Why? - ANSWER-Contact lenses can
absorb gases that can damage your eyes and they are difficult to remove during an
emergency situation.
Avoid wearing loose, draping clothing and dangling jewelry. Why? - ANSWER-It is easy
to drag these items through chemicals and across flames, which might create a
hazardous situation.
Interpret Scientific Diagrams What safety precautions should you take when the
following safety symbols are listed? - ANSWER-It is easy to drag these items through
chemicals and across flames, which might create a hazardous situation.
Define substance and chemistry. - ANSWER-Substance—any sample with a definite
composition; chemistry—the study of matter and the changes it undergoes
Where is ozone located in Earth's atmosphere? - ANSWER-90% in the stratosphere
What three elements are found in chlorofluorocarbons? - ANSWER-Carbon, fluorine,
and chlorine
What were common uses of CFCs? - ANSWER-Refrigerants, foams, propellants for
spray products
Scientists noticed that the ozone layer was thinning. What was occurring at the same
time? - ANSWER-Increased usage of CFCs
Why do chemists study regions of the universe? - ANSWER-Because chemists study
matter and matter is found throughout the universe.
Complete Solutions
Explain why the study of chemistry should be important to everyone. (1.1) - ANSWER-
Chemistry is the study of matter and everything and everyone is made of matter.
Define substance and give two examples of things that are substances. (1.1) -
ANSWER-A substance, which is also known as a chemical, is matter that has a definite
composition. Possible examples: table salt and table sugar
Describe how the ozone layer forms and why it is important. (1.1) - ANSWER-When
oxygen gas (0²) is exposed to ultraviolet radiation in the upper regions of the
stratosphere, the molecule breaks apart. The individual oxygen particles (O) combine
with other oxygen gas molecules to form ozone (O³). Ozone is important because it
forms a protective layer in the atmosphere that protects living organisms from harmful
radiation.
Explain why chlorofluorocarbons were developed and how they are used. (1.1) -
ANSWER-Chlorofluorocarbons were developed as a safe alternative to ammonia, a
common refrigerant. Chlorofluorocarbons are used as refrigerants, in foams, and as
propellants in spray cans.
Explain If cells have the ability to repair themselves after exposure to UVB, why are the
increasing levels of UVB in the atmosphere concerning scientists? (1.1) - ANSWER-
Cells have some ability to repair themselves, but some scientists believe that cells have
a limit in the amount of UVB exposure that can be tolerated.
Explain why the concentration of CFCs increased in the atmosphere. (1.1) - ANSWER-
The use of CFCs continued to increase.
Evaluate why it was important for Dobson's data to be confirmed by satellite photos.
(1.1) - ANSWER-All scientific hypotheses, tests, experiments, and data must be
independently confirmed to make them valid.
Good scientific models can be tested and used to make predictions. What did Molina
and Rowland's model of the interactions of CFCs and ozone in the atmosphere predict
would happen to the amount of ozone in the stratosphere as the level of CFCs
increased? - ANSWER-Their models predicted that as CFC concentrations increased,
ozone levels would decrease.
, Name three technological products that have improved our lives or the world around us.
- ANSWER-Possible answers: computer, internal combustion engine, and vaccinations.
Compare and contrast pure research and applied research. - ANSWER-Pure research
is done for the sake of knowledge. Applied research is done to solve a specific problem.
Is technology a product of pure research or applied research? Explain. - ANSWER-
Technology can be the product of either one. It can be a product of pure research when
scientists realize their discovery has a practical application. It can also be a product of
applied research when scientists perform research to solve a particular problem.
Wear goggles and an apron in the lab even if you are only an observer. Why? -
ANSWER-Harmful substances can get in your eyes and on your clothing if you are
performing an experiment or just watching it being performed.
Do not return unused chemicals to the stock bottle. Why? - ANSWER-The chemicals
might be contaminated and you do not want to contaminate the stock bottle.
Do not wear contact lenses in the laboratory. Why? - ANSWER-Contact lenses can
absorb gases that can damage your eyes and they are difficult to remove during an
emergency situation.
Avoid wearing loose, draping clothing and dangling jewelry. Why? - ANSWER-It is easy
to drag these items through chemicals and across flames, which might create a
hazardous situation.
Interpret Scientific Diagrams What safety precautions should you take when the
following safety symbols are listed? - ANSWER-It is easy to drag these items through
chemicals and across flames, which might create a hazardous situation.
Define substance and chemistry. - ANSWER-Substance—any sample with a definite
composition; chemistry—the study of matter and the changes it undergoes
Where is ozone located in Earth's atmosphere? - ANSWER-90% in the stratosphere
What three elements are found in chlorofluorocarbons? - ANSWER-Carbon, fluorine,
and chlorine
What were common uses of CFCs? - ANSWER-Refrigerants, foams, propellants for
spray products
Scientists noticed that the ozone layer was thinning. What was occurring at the same
time? - ANSWER-Increased usage of CFCs
Why do chemists study regions of the universe? - ANSWER-Because chemists study
matter and matter is found throughout the universe.
