Hi, this lesson is about the atmosphere.
The atmosphere is the ocean of air that surrounds the Earth. Scientist discovered that there are four layers of gases in the atmosphere.
We humans live in the troposphere, the first layer of the atmosphere. The air we breathe is 78% nitrogen (N) and 21% oxygen (O2), plus small amounts of Argon (Ar), carbon dioxide (CO2) and traces of other gases.
The stratosphere the second layer of the atmosphere, is made of ozone (O3). The ozone gas is made of three oxygen atoms. The ozone layer acts as a filter to block harmful sun-rays from entering the earth’s atmosphere. Also in the stratosphere is where you find vapor water (H2O).
The mesosphere is the third layer of atmosphere. In this layer the gases are far apart. This is also where we find meteors.
The thermosphere is the last and fourth layer of the atmosphere, there are a few gas molecules there. This layer extends into space, and is that farthest away from earth.
I learned this lesson from the book, “My First Book About Chemistry” by Donald M. Silver & Patricia J. Wynne.