Chemistry
Assertion (A): UV radiations break ozone into O2 and O.
Reason (R): Ozone hole is responsible for global warming and climate change.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
A is true but R is false.
Explanation— The Ozone layer is formed by the photolysis, it again absorbs UV radiation of comparatively longer wavelengths, breaking down again into oxygen molecule and oxygen atoms. Hence, the assertion (A) is true.
O3 ⟶ O2 + O
The ozone hole affects UV radiation reaching Earth's surface, leading to health and ecological issues. However, global warming and climate change are primarily caused by the greenhouse effect, driven by gases like CO2, CH4, and N2O — not by the ozone hole. Hence, the reason (R) is false.
Related Questions
Assertion (A): Photochemical smog is composed of oxides of nitrogen, ozone, peroxyacetyl nitrates and other organic compounds.
Reason (R): Photochemical smog is formed by the interaction of certain pollutants in cold weather conditions.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Atmosphere plays an important role in maintaining the temperature on earth.
Reason (R): Atmosphere absorbs some radiations coming from the sun and transmits near ultraviolet, visible and near infra red radiations.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Fill in the blanks:
(a) The pollutants such as NO2, SO2 and SO3 dissolved in the moisture of air are the cause of ……………
(b) Excessive release of carbon dioxide in the atmosphere is the cause of …………… effect which produces global warming.
(c) Ozone layer prevents the harmful …………… radiation of the sun to reach the earth.
(d) Decrease in the concentration of ozone in the stratosphere is the cause of the formation of …………… holes.
(e) Ozone depletion is mainly caused by the active …………… atoms generated from CFC in the presence of UV radiation.
Name any two :
(a) natural sources of atmospheric pollution.
(b) gases which are responsible for the formation of acid rain.
(c) particulate pollutants.