EARTH's Atmosphere

Earth's current atmosphere is _?_.

• 78% nitrogen, 21% oxygen, 0.9% argon and 0.037% carbon dioxide
• 78% oxygen, 21%nitrogen, 0.9% argon, 0.037% carbon dioxide
• 78% nitrogen, 21% argon, 1% oxygen
• 78% oxygen, 21% nitrogen, 1% carbon dioxide

What makes up 99% of the atmosphere?

• nitrogen
• oxygen
• carbon dioxide
• nitrogen and oxygen together

What does ozone in the atmosphere do?

• It absorbs and traps heat energy.
• It provides a place for water vapor to condense.
• It protects against harmful UV radiation.
• It helps plants grow.

What is the most common gas in the atmosphere?

• nitrogen
• oxygen
• water vapor
• carbon dioxide

Oxygen makes up approximately ____% of the gases in the atmosphere.

• 20
• 40
• 60
• 80

The most abundant gas in Earth's atmosphere is what?

• Oxygen

• Nitrogen

• Troposphere

• Helium

The _____ protects us from Earth's harmful UV rays.

• Ozone

• Troposphere

• Clouds

• Exosphere

Nitrogen makes up what percent of our atmosphere?

• 21%
• 1%
• 87%
• 78%

Why is Earth's atmosphere important?

• It is beautiful.
• It prevents pollution from happening.
• Life on Mars could not exist without it.
• Life on Earth could not exist without it.

Identify the most common gases found in Earth's atmosphere.

• carbon dioxide

• argon

• oxygen

• nitrogen