In a volume of air near Earth's surface today, ____ occupies 78 percent and ____ nearly 21 percent. ...

In a volume of air near Earth's surface today, ____ occupies 78 percent and ____ nearly 21 percent.
   a. nitrogen; oxygen
   b. hydrogen; oxygen
   c. oxygen; hydrogen
   d. nitrogen; water vapor
   e. hydrogen; helium

Question 2

Water vapor can best be described as a
   a. gas.
   b. cloud droplet.
   c. rain drop.
   d. snowflake.
   e. liquid.

Question 3

The most abundant gases in Earth's atmosphere by volume are
   a. carbon dioxide and nitrogen.
   b. oxygen and water vapor.
   c. nitrogen and oxygen.
   d. oxygen and helium.
   e. oxygen and ozone.

Question 4

The weight of all the air around Earth is a staggering 2000 trillion tons, or about 2 x 1018 kg.
   a. True
   b. False

Question 5

The lowest average air temperature can be found in the thermosphere.
   a. True
   b. False

Question 6

Storms rank in size from largest to smallest, as follows: middle-latitude cyclonic storm, hurricane, thunderstorm, tornado.
   a. True
   b. False

Question 7

Weather in the middle latitudes tends to move from east to west.
   a. True
   b. False

Question 8

Meteorology is the study of the atmosphere and its phenomena. The term itself goes back to a Roman emperor who, about 12 B.C., wrote a book on natural philosophy entitled Meteorologica.
   a. True
   b. False

Question 9

Fronts are a sharp change in temperature, humidity, and wind direction.
   a. True
   b. False

Question 10

Someone who says that the wind direction today is south likely means that the wind is blowing toward the south.
   a. True
   b. False