Gr 6 Science - Water & Atmosphere 3.1 & 3.2

What is water vapor?

Water vapor is water in the form of gas.

How does altitude affect air pressure?

Air pressure decreases as altitude increases.

What is altitude?

Altitude is the distance above sea level.

What is nitrogen?

Nitrogen is the most abundant gas in the atmosphere. It makes up a little more than 75% of the air we breathe. It occurs in all living things and makes up 3% of the weight of the human body.

What is weather?

Weather is the condition of the Earth's atmosphere at a particular time and place.

How does water vapor affect the atmosphere?

The amount of water vapor in the air varies from place to place and from time to time. It plays an important role in Earth's weather. Clouds form when water vapor condenses out of the air to form tiny droplets of liquid water or crystals of ice.

How much of oxygen makes up the atmosphere?

21%

How much of nitrogen makes up the atmosphere?

A little more than 75%.

Describe the differences between a mercury barometer and an aneroid barometer.

A mercury barometer is a glass tube with mercury. An aneroid barometer has a metal chamber and uses no liquid.

What particles are in the air?

Air contains tiny solid and liquid particles of dust, smoke, salt and chemicals.

What are some properties of air?

Air has atoms and molecules which have mass. Because air has mass it also has other properties, including density and pressure.

What is air pressure?

Air pressure is the pressure caused by the weight of a column of air pushing down on an area.

What is an aneroid barometer?

An aneroid barometer is an instrument that measures changes in air pressure without using a liquid.

How does altitude affect density?

As air pressure decreases so does density.

What is atmosphere?

Atmosphere is the envelope of gases that surrounds the planet.

What is carbon dioxide?

Carbon dioxide is much less than 1% of the air we breathe, but it is essential to life. Plants need it to produce food. Cells of animals break down food and give off carbon dioxide as a waste product. Burning fuels also release carbon dioxide.

How much of other gases make up the atmosphere?

The remaining 1%

What is a mercury barometer?

A mercury barometer is an instrument that measures changes in air pressure, consisting of a glass tube partially filled with mercury, with its open end resting in a dish of mercury.

How is air pressure affected by the density of the air?

Denser air exerts more pressure than less dense air.

What is density?

Density is the ratio of the mass of a substance to its volume (mass divided by volume).

How much of carbon dioxide makes up the atmosphere?

Less than 1%

What is oxygen?

Oxygen is the second most abundant gas even though it makes up only 21% of the air we breathe. Plants and animals take it directly from the air to release energy from food. It is involved in many other processes. For example, fire needs oxygen to burn.

What makes up the earth's atmosphere?

The earth's atmosphere consists of: nitrogen, oxygen, carbon dioxide, water vapor, other gases and particles of liquids and solids.

What are the other gases of the atmosphere?

While nitrogen and oxygen make up almost 99% of dry air, argon makes up most of the other 1%. The remaining gases are called trace gases because only small amounts are present.