Question : Assertion : Contribuition of CO_(2), CH_(4), CFCs " and " N_(2)O towards greenhouse effect is respectively 60%, 6 %, 14 % and 20 %. Reason : Greenhouse gases are radioactively active gases which prevent the short wavelength radiations emitted by earth to escape into space.

Question : Assertion : Contribuition of CO_(2), CH_(4), CFCs " and " N

1.	Question : Assertion : Contribuition of CO_(2), CH_(4), CFCs " and " N_(2)O towards greenhouse effect is respectively 60%, 6 %, 14 % and 20 %. Reason : Greenhouse gases are radioactively active gases which prevent the short wavelength radiations emitted by earth to escape into space.
Answer» (a) Both, Assertion and Reason, are true and Reason is the correct EXPLANATION of Assertion (b) Both, Assertion and Reason, are true but Reason is not the correct explanation of Assertion (c) If Assertion is true but Reason is false (d) If Assertion is false but Reason is true Solution :The gases which are transparent to solar radiation but retain and partially reflect back long wave heat RADIATIONS are called greenhouse gases (GHGs). Greenhouse gases are essential for keeping the earth warm and hospitable. The various greenhouse gases are `CO_(2)` (warming EFFECT 60%) , `CH_(4)` (effect 20%), CHLOROFLUOROCARBONS or CFCs (14%) and nitrous oxide `(N_(2)O, 6%)`. Others of minor significance are water VAPOURS and ozone.