The ozone layer
A shield against ultraviolet rays.
Oxygen's second job
We breathe oxygen. Some oxygen in the atmosphere is also changed into another form.
What does that other form do?
What this lesson covers
The idea
Some atmospheric oxygen is converted to ozone, a three-atom oxygen molecule, forming the ozone layer, which shields Earth by blocking harmful ultraviolet (UV) rays from the Sun that can damage living cells.
Oxygen's second job
We breathe oxygen. Some oxygen in the atmosphere is also changed into another form.
What does that other form do?
- It shields us from harmful ultraviolet rays
- It makes clouds
- It makes the Earth hotter
Make the shield
Press Next step.
A sunscreen for Earth
Oxygen allows us to breathe, but some of it is converted into ozone, a three-atom oxygen molecule. The ozone layer blocks harmful ultraviolet rays from the Sun.
Some oxygen changes into ozone (a three-atom oxygen molecule), forming the ozone layer. It blocks harmful ultraviolet (UV) rays from the Sun that can damage living cells.
Notes
The ozone layer blocks harmful UV rays.
Check yourself
Ozone is a molecule made of …
The ozone layer blocks harmful …
UV rays can …
The ozone layer is made from …
- three oxygen atoms — correct. Yes!
- two oxygen atoms. That is the oxygen we breathe.
- one carbon atom. Ozone is made of oxygen atoms.
- sound waves. It blocks UV rays.
- ultraviolet (UV) rays from the Sun — correct. Yes!
- rain. It blocks UV rays.
- make plants grow. Harmful UV rays can damage living cells.
- cool the Earth. Harmful UV rays can damage living cells.
- damage living cells — correct. Yes!
- some of the oxygen in the atmosphere — correct. Yes!
- carbon dioxide only. It is made from some of the oxygen in the atmosphere.
- water vapour. It is made from oxygen.