Ozone layer shields from UV
A poison that protects us.
High in the sky
High in the atmosphere there is a layer of a gas called ozone.
What does this layer do for life on the earth's surface?
What this lesson covers
The idea
Ozone (O3) is a molecule of three oxygen atoms; though a deadly poison, at the higher levels of the atmosphere it shields the earth's surface from the Sun's ultraviolet radiation, which is highly damaging to organisms.
High in the sky
High in the atmosphere there is a layer of a gas called ozone.
What does this layer do for life on the earth's surface?
- It shields the surface from the Sun's ultraviolet radiation
- It gives us the oxygen we breathe
- It makes the Sun's light brighter
Molecules and shield
Open both tabs.
Poison below, shield above
Ozone is a molecule with three oxygen atoms. It is a deadly poison. But at the higher levels of the atmosphere it does an essential job. It shields the earth's surface from the Sun's UV radiation, which is highly damaging to organisms. For example, it is known to cause skin cancer in human beings.
Ozone (O₃) is a molecule of three oxygen atoms; though a deadly poison, at the higher levels of the atmosphere it shields the earth's surface from the Sun's ultraviolet radiation, which is highly damaging to organisms.
Notes
Ozone (O₃) is a poison, but high in the atmosphere it shields us from UV radiation.
Check yourself
How many oxygen atoms are in one molecule of ozone?
Answer: 3
Ozone, O₃, is a molecule formed by three atoms of oxygen.
What does the ozone layer at the higher levels of the atmosphere do?
Which statement about ozone, O₃, is correct?
What is one example of the damage that UV radiation can do to human beings, according to the book?
- It gives off ultraviolet radiation. UV radiation comes from the Sun. The ozone layer shields the surface from it.
- It supplies the oxygen that aerobic life needs. That oxygen is O₂. Ozone, O₃, is a different molecule and a deadly poison.
- It shields the earth's surface from the Sun's UV radiation — correct. Yes!
- It is a deadly poison, yet at higher levels of the atmosphere it performs an essential function — correct. Yes!
- It is the oxygen that aerobic life needs. The oxygen that aerobic life needs is O₂. Ozone is a deadly poison.
- Its molecule has two oxygen atoms. Its molecule has three oxygen atoms. Two atoms make O₂.
- It helps the body to digest food. UV radiation is highly damaging to organisms. Digestion is done by enzymes.
- It is known to cause skin cancer — correct. Yes!
- It protects the surface of the earth. It is the ozone layer that protects the surface of the earth. UV radiation is highly damaging.