Between about 15 and 35 km above the Earth's surface
CHEMISTRY · Multi-part · GCSE · Chemistry · Chemistry of the Atmosphere · Chemistry of the Atmosphere
Problem
Between about 15 and 35 km above the Earth's surface, the concentration of ozone molecules is higher than in other regions of the atmosphere. Absorption of radiation in the ultraviolet region of the electromagnetic spectrum by ozone molecules can dissociate the molecules into atomic and molecular oxygen.
(1) What is ozone?
(2) Outline what happens to the atoms of oxygen of an ozone molecule when ultraviolet radiation is absorbed by an ozone molecule in order to cause the molecule to dissociate.
(3) What effect does this molecular dissociation have on the amount of ultraviolet radiation reaching the surface of the Earth?
(4) Why is this effect so important for life on the Earth?
(5) What would the effect be if the concentration of ozone molecules in the atmosphere were to be reduced?
(6) Where in the world has this effect already been observed?
(7) Which countries are most at risk from the effects of this 'ozone hole'?
(8) What have scientists—and their influence over governments—done to try to prevent further decreases of ozone in the ozone hole region?