What gas makes up 78% of our atmosphere?

Nitrogen

When a candle burns, what happens to the oxygen?

It is burned up.

The condition of Earth’s atmosphere at a particular time and place is called….

Weather

T or F Smoke is made up of solid particles in the air.

True

What gas makes up 21% of our atmosphere?

Oxygen

The atmosphere protects us from harmful rays of the sun plus…..

meteoroids

Water vapor is a liquid and steam is a gas.

True

The more molecules in a volume of air, the greater it’s …..

Density

Plants take in carbon dioxide and give off ….

Oxygen

Air has mass because it is composed of …..

Atoms and Molecules

Density increases if we put ___ molecules in it.

More

The amount of oxygen is less at high or low altitudes?

High

What do we call an instrument used to measure air pressure?

Barometer

As air pressure decreases, what happens to the column of mercury?

It sinks

Mercury is one type of barometer. Name another type.

Aneroid

Inches of mercury is one way we express air pressure. What is another?

Millibars

What is another word for elevation?

Altitude

Air pressure is weakest.

On a mountain top