Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Ozone () is a molecule formed by three atoms of oxygen. While oxygen () is essential for all aerobic forms of life, ozone is a deadly poison at the ground level.
The ozone layer is found in the stratosphere. It shields the surface of the earth from ultraviolet () radiation from the Sun which is highly damaging to organisms (e.g., causing skin cancer in humans).
Ozone at the higher levels of the atmosphere is a product of radiation acting on oxygen () molecules. The higher energy radiations split apart some molecular oxygen into free oxygen () atoms.
The decline of the ozone layer in the 1980s has been linked to synthetic chemicals like chlorofluorocarbons (), which are used as refrigerants and in fire extinguishers.
In 1987, the United Nations Environment Programme () succeeded in forging an agreement to freeze production at 1986 levels to prevent further ozone depletion.
📐Formulae
💡Examples
Problem 1:
State the role of radiation in the formation of the ozone layer.
Solution:
then
Explanation:
The high energy radiation breaks down the stable oxygen molecule () into two highly reactive free oxygen () atoms. These nascent oxygen atoms then react with the remaining oxygen molecules to form ozone ().
Problem 2:
Why is the damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
Solution:
Damage to the ozone layer allows harmful rays to reach Earth, causing skin cancer and cataracts. The step taken is the agreement to freeze production.
Explanation:
Since release chlorine atoms that catalyze the destruction of , international protocols like the Montreal Protocol were established to mandate the use of -free refrigerators and decrease industrial emission of ozone-depleting substances.