Ozone depleting substances are chemicals that destroy the earth’s protective ozone layer. They include: chlorofluorocarbons (CFCs) halons. carbon tetrachloride (CCl4)
What are ozone depleting substances give examples?
ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform. ODS are generally very stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere.
What can deplete the ozone layer?
Chlorofluorocarbons or CFCs are the main cause of ozone layer depletion. These are released by solvents, spray aerosols, refrigerators, air-conditioners, etc. The molecules of chlorofluorocarbons in the stratosphere are broken down by the ultraviolet radiations and release chlorine atoms.
Which products contain ozone depleting substances answer?
The main uses of ozone depleting substances include:
- CFCs and HCFCs in refrigerators and air conditioners,
- HCFCs and halons in fire extinguishers,
- CFCs and HCFCs in foam,
- CFCs and HCFCs as aerosol propellants, and.
- methyl bromide for fumigation of soil, structures and goods to be imported or exported.
What is ozone depletion Class 12?
– Ozone layer depletion is the gradual thinning of the earth’s ozone layer in the upper atmosphere caused due to release of chemical compounds containing gaseous bromine or chlorine from industries and human activities. – Chlorofluorocarbons are, therefore, termed major ozone-depleting substances (ODS).
What are ozone-depleting substances and how do they deplete the ozone layer?
The main causes of ozone depletion and the ozone hole are manufactured chemicals, especially manufactured halocarbon refrigerants, solvents, propellants, and foam-blowing agents (chlorofluorocarbons (CFCs), HCFCs, halons), referred to as ozone-depleting substances (ODS).
How do CFCs destroy ozone?
Once in the atmosphere, CFCs drift slowly upward to the stratosphere, where they are broken up by ultraviolet radiation, releasing chlorine atoms, which are able to destroy ozone molecules. When sunlight returns in the spring, the chlorine begins to destroy ozone.
Which gas is found in Ozonosphere?
The ozone layer or ozone shield is a region of Earth’s stratosphere that absorbs most of the Sun’s ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.
How do ozone depleting substances affect ozone shield?
Ozone depleting substances are man-made gases that destroy ozone once they reach the ozone layer. The ozone layer sits in the upper atmosphere and reduces the amount of harmful ultra violet radiation that reaches Earth from the sun.
What is ozone depletion in biology?
Ozone depletion is a global reduction in the thickness of the ozone layer, caused by chlorine and bromine atoms which reach the stratosphere. The ozone hole is a seasonal thinning of ozone above the Antarctic.
What is ozone depletion causes and effects?
The main effect of ozone depletion is an increase in UV-B rays reaching the earth’s surface. Causes : chlorofluorocarbon (CFCs), halons, and other compounds deplete the ozone layer. CFCs and halons break down into chlorine and bromine which in turn destroy the ozone layer.
How do ozone depleting substances destroy ozone molecules?
Ozone Depletion. When chlorine and bromine atoms come into contact with ozone in the stratosphere, they destroy ozone molecules. One chlorine atom can destroy over 100,000 ozone molecules before it is removed from the stratosphere.
