Earth's Atmosphere

What are the two main gases that make up Earth's atmosphere?

• Nitrogen and carbon dioxide

• Oxygen and carbon dioxide

• Nitrogen and oxygen

• Oxygen and hydrogen

What is atmospheric pressure?

• The weight of the gases in the atmosphere pressing down on Earth

• The temperature of the atmosphere

• The speed of the wind in the atmosphere

• The amount of sunlight reaching the Earth

Which layer of the atmosphere is closest to Earth's surface?

• Stratosphere

• Mesosphere

• Troposphere

• Exosphere

Where does all weather occur in the atmosphere?

• Stratosphere

• Mesosphere

• Troposphere

• Thermosphere

What are greenhouse gases?

• Gases that trap heat near Earth's surface

• Gases that cool the Earth's surface

• Gases that are only found in the stratosphere

• Gases that are only found in the exosphere

Which gases are the most common greenhouse gases?

• Nitrogen and oxygen

• Water vapor and carbon dioxide

• Methane and ozone

• Hydrogen and helium

What effect do recent increases in carbon dioxide levels have?

• They decrease global temperatures

• They raise temperatures and change weather patterns

• They have no effect on the climate

• They increase the amount of oxygen in the atmosphere

What does the ozone layer in the stratosphere do?

• Absorbs harmful ultraviolet radiation from the Sun

• Traps heat near Earth's surface

• Increases the amount of carbon dioxide

• Produces oxygen for the atmosphere

What are CFCs known to do in the atmosphere?

• Increase the amount of oxygen

• Break apart ozone molecules

• Trap heat near Earth's surface

• Absorb ultraviolet radiation

What is the major cause of skin cancer and sunburn?

• Carbon dioxide

• Ultraviolet radiation

• Nitrogen

• Oxygen