PS Module 2

Question 1

• Absolute humidity

Answer 1

The mass of water vapor contained in a certain volume of air

Question 2

• Greenhouse effect

Answer 2

The process by which certain gases (principally water vapor, carbon dioxide, and methane) trap heat that radiates from earth

Question 3

• Humidity

Answer 3

The moisture content of the air

Question 4

• Parts per million

Answer 4

The number of molecules (or atoms) of a substance in a mixture for every 1 million molecules (or atoms) in that mixture

Question 5

• Relative humidity

Answer 5

A quantity expressing humidity as a percentage of the maximum absolute humidity for that particular temperature.

Question 6

• What does sweat evaporating from the body do to the body?

Answer 6

Evaporating sweat cools your skin down.

Question 7

• Does sweat evaporate quicker or slower on humid days and what does this mean for your body temperature?

Answer 7

Slower since the air already has water in it. The higher the humidity, the slower your sweat evaporates, and the slower you get cooled.

Question 8

• If a glass of water is set outside and the relative humidity is 90% one day and 60% another, which day will more water evaporate?

Answer 8

Since the humidity is lower on the second day, the water will evaporate more quickly.

Question 9

• If a glass of water is set outside and the relative humidity is 100%, how quickly will the water evaporate?

Answer 9

It won’t because the air is already saturated with water allowing no more to be added.

Question 10

• Why does sweating cool people down?

Answer 10

Sweat cools you off because when it evaporates, it takes energy from your skin. When energy leaves your skin, it gets cooler.

Question 11

• What are the percentages of nitrogen & oxygen in the air?

Answer 11

Dry air is 78% nitrogen & 21% oxygen.

Question 12

• What would happen if all the carbon dioxide was removed from earth’s air supply?

Answer 12

First, the earth would be colder because the carbon dioxide helps absorb the sun’s light & make the earth warmer. Second, the plants would die of starvation because they need carbon dioxide for photosynthesis which helps them make food.

Question 13

• What would happen if all the ozone was removed from earth’s air supply?

Answer 13

Ultraviolet light would kill all living things because ozone absorbs the harmful ultraviolet light.

Question 14

• What would happen if the concentration of oxygen suddenly increased in the earth’s air supply?

Answer 14

Combustion activities (burning) would all incease. Forest fires would increase in frequency and ferocity. Lifespans would decrease because combustion in the body would speed up and increase heart rate, blood pressure, & hyperactivity.

Question 15

• If astronomers found another planet similar to earth in size, sun, distance from the sun, etc… what would need to be the same in order to have the the same temperature?

Answer 15

The same composition in the air with all the same greenhouse gases.

Question 16

• What makes up the majority of the air that we exhale?

Answer 16

Nitrogen

Question 17

• Do we exhale more carbon dioxide or oxygen?

Answer 17

Oxygen

Question 18

• Is global warming happening today? Explain.

Answer 18

No. The average global temperature has been reasonably constant for the past 70 years.

Question 19

• How do you convert ppm to percent?

Answer 19

Divide ppm by 10,000 (shortcut=four zeroes means move decimal four places to the left making it smaller)

Question 20

• How do you convert percent to ppm?

Answer 20

Multiply percent by 10,000 (shortcut=four zeroes means move decimal four places to the right making it bigger)

Question 21

• Is the air cleaner today than 20 years ago?

Answer 21

Yes, much cleaner.

Question 22

• What is a cost/benefit analysis?

Answer 22

It attempts to determine whether or not to take an action by determining the benefits of that action as well as the costs. If the benefit outweighs the cost, then the action should be taken.

Question 23

• What does a catalytic converter do in a car?

Answer 23

Converts carbon monoxide in a car’s exhaust to carbon dioxide.

Question 24

• What does a scrubber do in a smokestack?

Answer 24

Traps sulfur oxides and keeps them from being emitted into the air.

Question 25

• What is the difference between ground- level ozone which is considered a pollutant and ozone in the ozone layer which is considered vital?

Answer 25

Ground-level ozone is where we can breathe it & is poisonous. No one breathes the ozone high up in the ozone layer so its toxicity is irrelevant, but it is vital to block the sun’s ultraviolet rays.