Earth’s Atmosphere and Clouds

Question: Which of these is not a greenhouse gas?

Answer: Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone, and halogenated fluorocarbons.

Question: Which altitude of clouds is most likely to produce rain?

Answer: Rain generally falls only from clouds at middle and low altitudes. High clouds are made of ice crystals and may form snow, but snow generally evaporates before it hits the ground.

Question: Which of these is not part of the atmosphere?

Answer: The atmosphere is composed of layers. The lowest is the troposphere, and the highest is the exosphere.

Question: Which of these is lighter than air?

Answer: Helium, a gas, is found in natural gas and is used to lift balloons, in many scientific applications, and in underwater diving.

Question: What do scientists call a cloud that does not carry rain?

Answer: A rainless cloud is called a dead cloud. Such a cloud is common in dry, cool weather.

Question: How fast does a raindrop fall, in meters per second, during a cloudburst?

Answer: In a heavy rainfall, a drop of rain falls at about 23 feet per second (7 meters per second). In a drizzle the speed is slower, about 13 feet a second (4 meters a second).

Question: Which of the following is not a type of cloud?

Answer: There are three basic classifications of clouds: cirrus, stratus, and cumulus.

Question: What is a cloud formed behind an airplane called?

Answer: Contrails are long, thin clouds sometimes observed behind an airplane flying in clear, cold, humid air.