The Air Around You

How long will the candle burn?

• Remember the activity we did yesterday?

• Any comments? Or reflections?

What is the fire triangle?

What is in the air that fire needs to burn?

Oxygen!!!

Living things also need oxygen, we love oxygen.

Fuel, Heat, and

Air

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

A question for you…

What would conditions on Earth be

like without the atmosphere? • Water could not exist as a liquid on Earth’s

surface.• Earth would be exposed to meteoroids and

dangerous radiation from the sun. • There would be no life on Earth without the

oxygen and other gases that living things need.

The Atmosphere

• Earth's atmosphere is the layer of gases that surrounds the planet.

The Atmosphere – Living Things

•Earth’s atmosphere makes conditions on Earth suitable for living things.

Composition of the Atmosphere• Atmosphere is made up of different kinds of gases

necessary for living things.– Such as nitrogen, oxygen, carbon dioxide, water

vapor, and other gases, as well as particles of liquids and solids.

Nitrogen

• Nitrogen is the most abundant gas in the atmosphere.

• Nitrogen is essential to living things. • Organisms must have nitrogen in

order to grow and to repair body cells.

Oxygen • Oxygen is the second most abundant gas

in the atmosphere. • Plants and animals take oxygen directly

from the air and use it to release energy from food in a usable form.

Carbon Dioxide (CO2)

• It is present in the air in small amounts• It is essential to all life. • It is given off by animals as a waste product.

• Plants must have CO2 to produce food.

• Burning fuels such as coal and gasoline, releases CO2 in the atmosphere which could be raising Earth’s temperature.

Carbon Dioxide   • Even though the atmosphere contains

only a small amount of carbon dioxide, it is essential to life.

• Plants must have carbon dioxide to produce food.

• When fuels such as coal and gasoline are burned, they release carbon dioxide.– Burning these fuels increases the amount

of carbon dioxide in the atmosphere. – Rising carbon dioxide levels may be raising

Earth's temperature. (Global warming?)

A question for you…How would the amount of carbon dioxide

and oxygen in the atmosphere change if there were no plants? If there were no animals?

Without plants there would be less oxygen and more carbon dioxide.

Without animals there would be less carbon dioxide and more oxygen.

Water Vapor   • Air is not dry because it contains

water vapor. • Water vapor is water in the form of

a gas. – The amount of water vapor in the air

varies greatly from place to place and from time to time.

• Water vapor plays an important role in Earth's weather.

• Clouds form when water vapor condenses.

Particles

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

• Sometimes you can see the particles but most of them are too small to see.