Composition of Earth's Atmosphere

What is the percentage of trace gases in the atmosphere?

• 0.2%

• 0.9%

• 20.9%

• 78.0%

What is the second most abundant gas in the atmosphere?

• Argon

• Oxygen

• Nitrogen

• Carbon Dioxide

What is the role of trace gases in the atmosphere?

• They make up the majority of the atmosphere.

• They are essential for life.

• They are present in very small amounts.

• They are the main source of oxygen.

What process did algae and green plants begin that affected atmospheric gases?

• Respiration

• Photosynthesis

• Fermentation

• Combustion

What are the primary components of the atmosphere?

• Oxygen and carbon dioxide

• Oxygen and nitrogen

• Nitrogen and hydrogen

• Carbon dioxide and hydrogen

At approximately what altitude does the exosphere begin?

• A) 10 km

• B) 50 km

• C) 700 km

• D) 1000 km

In which layer of the atmosphere do we live?

• Exosphere

• Mesosphere

• Troposphere

• Thermosphere

What does ozone absorb from the sun?

• Infrared radiation

• Ultraviolet radiation

• Visible light

• X-rays

What layer of the atmosphere does solar radiation first hit?

• Troposphere

• Stratosphere

• Mesosphere

• Thermosphere

nitrogen, oxygen, carbon dioxide, argon, water vapor

• atmospheric gases

• stratosphere

• atmospheric pressure

• climate

• global winds