By: Brian K Chen
Content Intro
Atoms and elements
The natural way
What is the ozone layer
The common perception
Scientific truth
The result
How are CFCs gotten rid of
What’s been done
•What should we do•Interesting facts•Sources
Intro CFC is short for Chloro Fluoro Carbon.
It is a man mad substance and is harmful to the environment, more specifically, the ozone layer.
It is emitted through many daily appliances, at first, people didn’t even know that it was bad.
Nowadays, steps are being made to correct things.
Atoms and elements Oxygen
-1 oxygen atom is not very important
-2 oxygen atoms=the oxygen in the air we breathe
-3 oxygen atoms=an ozone molecule
Flourine
Carbon
Chlorine
The natural way Normally, the process of producing ozone is very
balanced
One ozone molecule breaks into two oxygen atoms and one oxygen atom.
The two oxygen atoms joins with one oxygen atom form another ozone molecule
The one oxygen atom joins with two oxygen atoms to form another ozone molecule.
The process is very balanced.
What is the ozone layer The ozone layer is part of the stratosphere and is made
mostly by one element, oxygen.
Ozone itself is a substance. One ozone molecule is made of 3 oxygen molecules.
The Ozone layer is part of the stratosphere which is one section of the atmosphere
Without the ozone layer, we would be exposed to ultra-violet radiation from the sun.
This would cause widespread skin cancer and other problems
What is the common perception
Where do CFCs come from coolants such as refrigerators and air conditioners.
Aerosols like antiseptic sprays
The scientific truth Chloro flouro carbons can be written as CF3Cl
The C is carbon-1 atom
F is Flourine-3 atom
Cl is Chlorine-1 atoms
After ultraviolet radiation from the sun, one chlorine atom breaks off we have CF3+Cl
The single Chlorine atom is the most dangerous.
3 3CFCl CF Cl
The scientific truth The single chlorine atom will, after it has broken
off, combine with ozone molecule and break it into 1 oxygen atom and one oxygen molecule with two atoms.
Then it will combine with one of the oxygen atoms.
3 2Cl O ClO O
The scientific truth After wards, the combination will combine with an
oxygen atom and break down into another oxygen molecule.
The following word equations explains this
2ClO O Cl O
The result The process was balanced but now the CFCs are
causing ozone molecules to be destroyed faster than they are being created
That is real bad
Why is the CFC so dangerous The problem is how long it takes for a CFC molecule to
leave the stratosphere
Normal physical means cannot get rid of it
On average, one CFC molecule can destroy 100,000 Ozone molecules in its life time
There are only a few ways of getting rid of it
How is the CFC gotten rid of When the chlorine atom collides with other molecules
such as hydrocarbons, it forms hydrogen chloride which can leave the atmosphere dissolved in water.
Other way is to let the atom slowly drift out
What has been done There is the Montreal protocol
-It links countries together
-In this agreement, they all set aims together to cut producing of CFCs
-Singapore is included
-It has been changed many times to improve it
What should we do????? We should check if the goods we buy such as
refrigerators don’t have CFC
Do projects like this to raise public awareness
Interesting facts In some urban areas although the ozone layer is
thinner, there is actually less Ultra-violet radiation reaching the ground
This is because of pollution
The carbon dioxide and smog in the air actually helps to block the ultra-violet radiation!!!
Sources Wikipedia
Collins advanced science chemistry
http://answers.ask.com/Science/Nature/where_do_cfc_come_from
Thanks for watching
!!!