Greenhouse Effect and the Ozone Layer

Question 1

What is ozone?

Answer 1

A rare, unstable, very reactive molecule of 03

Question 2

What is the ozone layer?

Answer 2

1. Layer of ozone in the stratosphere that protects us from about 90% of the sun’s harmful UV rays
2. These are very high energy UV rays, so without it, would be deadly - 10% UV is enough to burn us.

Question 3

How does ozone form?

Answer 3

1. When an oxygen molecule has absorbed enough of the Sun’s radiation, it splits apart, forming 2 sperate molecules.
2. The free atoms can then bind to another O2 molecule to form O3.

Question 4

Why is ozone rare?

Answer 4

1. It breaks down naturally b/c it’s natural form is O2

2. The Sun’s radiation makes it decay into O2 - O3 is easier to split apart b/c it is unstable in this form.

Question 5

Why is the ozone layer thinning?

Answer 5

1. Chloroflorocarbons (CFCs) containing carbon, fluorine and chlorine released from aerosols, old fridges etc. deplete ozone.
2. When the CFCs enter the atmosphere, the Sun’s radiation splits them apart into their constituent elements.
3. Chlorine tends to bind with oxygen, which depletes the levels of of oxygen in the ozone layer, causing it to thin.

Question 6

Why is it bad for the ozone layer to thin?

Answer 6

1. More harmful, short wavelength, ionising radiation will be able to reach the earth, which would’ve been protected by the thinning natural layer.
2. This is bad b/c since UV is ionising, a single photon has enough energy to add or remove electrons from the atoms of healthy cells in the body, potentially causing unwanted genetic mutations, chemical reactions or the cell to become cancerous.

Question 7

How have we reduced the danger of CFCs?

Answer 7

They’ve been banned worldwide.