The most abundant gases in the air are 

• argon and ozone.

• oxygen and nitrogen

• carbon dioxide and methane.

Gases flow and swirl in the 

• troposphere

• stratosphere

• thermosphere

Which statement is NOT true?

• Liquid water exists only on Earth's surface

• Most water on Earth is found in the oceans

• About 3 percent of water on Earth is freshwater

What is the "layer where weather occurs"?

•  exosphere

• mesosphere

• stratosphere

• thermosphere

• troposphere

What is the " least dense layer of the atmosphere "?

•  exosphere

• mesosphere

• stratosphere

• thermosphere

• troposphere

What is the "middle layer of the atmosphere"?

•  exosphere

• mesosphere

• stratosphere

• thermosphere

• troposphere

What is the "process by which a liquid changes to a gas"?

• condensation

• evaporation

• precipitation 

• transpiration

What is the "process by which a gas changes to a liquid"?

• condensation

• evaporation

• precipitation 

• transpiration

What is the "any moisture that falls from clouds"?

• condensation

• evaporation

• precipitation 

• transpiration

Earth system of water?

• atmosphere 

• biosphere 

• geosphere 

• hydrosphere