2. The atmosphere is a layer of gases that wraps around
Earth like a blanket
It holds in heat, contains the air we breathe, protects living
things from the sun’s harmful radiation, and helps the planet
recycle its water supply
The atmosphere is made up of nitrogen and oxygen with
small amounts of carbon dioxide and water vapor
Earth is the only planet who’s atmosphere is formed of these
gases
Carbon dioxide is a greenhouse gas that absorbs Earth’s heat
and keeps the planet warm
Water vapor is a greenhouse gas that plays an important role
in weather
Earth’s atmosphere is also made up of particles like soil,
pollen, grains, and soot that help form clouds
3.
4. Weather: the state of the atmosphere at a certain
place and time
It changes all the time
We can observe weather by measuring properties of the
air like temperature, humidity, air pressure, and wind
These can also help us predict weather
6. Humidity: the amount of water vapor air can hold
Warm air holds more water vapor than cool air
Air that is humid holds a lot of water vapor
Humid air is more likely to produce clouds and
precipitation
7. Air has weight
We live at the bottom of Earth’s atmosphere, so there is a lot of
air above us
The force of the weight of the air pushing down on us is air
pressure
Air pressure is not the same everywhere
Temperature affects air pressure
Low air pressure
Air gets warmer gas particles get farther apart and rises
Rising air presses down with less force and creates a low area of
pressure
Clouds form where low pressure forms
High air pressure
Air gets cooler gas particles get closer together and sink
Sinking air presses down with more force and creates a high area of
pressure
8. Wind is the movement of air from areas of high
pressure to areas of low pressure
When the difference of pressure great, the wind blows
faster
When the difference of pressure is small, the wind
blows slower