Which gas makes up the largest portion of Earth's atmosphere?

Oxygen (about 78%) Nitrogen (about 78%) Carbon dioxide (about 78%) Hydrogen (about 78%)

In which layer of the atmosphere does all weather occur?

Stratosphere Troposphere Mesosphere Thermosphere

In which layer of the atmosphere is the ozone layer found?

Troposphere Stratosphere Mesosphere Exosphere

What does the ozone layer protect life on Earth from?

Meteoroids hitting Earth Harmful ultraviolet (UV) radiation from the Sun Strong gravitational forces Radio waves from space

Which layer of the atmosphere burns up most meteoroids before they reach Earth's surface?

Troposphere Stratosphere Mesosphere Exosphere

Where do the Northern and Southern Lights (auroras) occur?

Troposphere Stratosphere Mesosphere Thermosphere

Why does temperature decrease as you go higher in the troposphere?

It is closer to the cold of outer space The air is less dense and absorbs less heat radiated from Earth's surface The ozone layer blocks heat from rising Wind carries heat away faster at higher altitudes

Which gas in the atmosphere is most responsible for the greenhouse effect that keeps Earth warm?

Nitrogen Oxygen Carbon dioxide (CO₂) Argon

What is the outermost layer of Earth's atmosphere?

Thermosphere Mesosphere Stratosphere Exosphere

What would Earth most likely be like without its atmosphere?

Nothing much would change Earth would spin faster Extreme temperatures, no liquid water, and no protection from radiation — unable to support life Earth would be covered entirely in ice

Which gas, produced by plants, makes up about 21% of Earth's atmosphere?

Nitrogen Carbon dioxide Oxygen Argon