Chapter 1

Define substance and give two examples of things that are substances.

Describe how the ozone layer forms and why it is important.

Explain why chlorofluorocarbons were developed and how they are used.

Explain If cells have the ability to repair themselves after exposure to UVB, why do the increasing levels of UVB in the atmosphere concern scientists?

Explain why the concentration of CFCs increased in the atmosphere.

Explain why there are different branches of chemistry

Explain why scientists use mass instead of weight for their measurements.

Summarize why it is important for chemists to study changes in the world at a submicroscopic level.

Infer why chemists use models to study submicroscopic matter.

Evaluate How would your mass and weight differ on the Moon? The gravitational force of the Moon is one-sixth the gravitational force on Earth.

Evaluate If you put a scale in an elevator and weigh yourself as you ascend and then descend, does the scale have the same reading in both instances? Explain your answer.

Explain why scientists do not use a standard set of steps for every investigation they conduct.

Differentiate Give an example of quantitative and qualitative data.

Evaluate You are asked to study the effect of temperature on the volume of a balloon. The balloon’s size increases as it is warmed. What is the independent variable? The dependent variable? What factor is held constant? How would you construct a control?

Distinguish Jacques Charles described the direct relationship between temperature and volume of all gases at constant pressure. Should this be called Charles’s law or Charles’s theory? Explain.

Explain 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?

Name three technological products that have improved our lives or the world around us.

Compare and contrast pure research and applied research.

Summarize the reason behind each of the following. a. Wear goggles and an apron in the lab even if you are only an observer. b. Do not return unused chemicals to the stock bottle. c. Do not wear contact lenses in the laboratory. d. Avoid wearing loose, draping clothing and dangling jewelry.

Ozone Where is ozone located in Earth’s atmosphere?

What three elements are found in chlorofluorocarbons?

CFCs What were common uses of CFCs?

If three oxygen particles are needed to form ozone, how many units of ozone could be formed from 6 oxygen particles? From 9? From 27?

Why is chemistry called the central science?

Which measurement depends on gravitational force mass or weight? Explain.

Which branch of chemistry studies the composition of substances? The environmental impact of chemicals?

Predict whether your weight in the city of Denver, which has an altitude of 1.7 km above sea level, will be the same as, more than, or less than your weight in New Orleans, a city located at sea level.

The text tells you that, “1 trillion atoms could fit onto a period at the end of this sentence.” Write out the number 1 trillion using the correct number of zeros.

How does qualitative data differ from quantitative data? Give an example of each.

What is the function of a control in an experiment?

What is the difference between a hypothesis, a theory, and a law?

Label each of the following pieces of data as qualitative or quantitative. a. A beaker weighs 6.6 g. b. Sugar crystals are white and shiny. c. Fireworks are colorful.

If evidence you collect during an experiment does not support your hypothesis, what should happen to that hypothesis?

One carbon (C) and one ozone (O \(_{3} )\) react to form one carbon monoxide (CO) and one oxygen gas \(\left(\mathrm{O}_{2}\right)\) particle. How many ozone particles are needed to form 24 particles of oxygen gas (O \(_{2} ) ?\)

If your lab procedure instructs you to add two parts acid to each one part of water and you start with 25 mL of water, how much acid will you add, and how will you add it?

Classify CFCs break down to form chemicals that react with ozone. Is this a macroscopic or a microscopic observation?

Infer A newscaster reports, “The air quality today is poor. Visibility is only 1.7 km. Pollutants in the air are expected to rise above 0.085 parts per million (ppm) in the next eight-hour average. Spend as little time outside today as possible if you suffer from asthma or other breathing problems.” Which of these statements are qualitative and which are quantitative?

Ozone Depletion Based on your knowledge of chemistry, describe the research into depletion of the ozone layer by CFCs in a timeline.

CFC Reduction Research the most recent measures taken by countries around the world to reduce CFCs in the atmosphere since the Montreal Protocol. Write a short report describing the Montreal Protocol and more recent environmental measures to reduce CFCs.