Q59 of 163 Page 242

O2 is converted into O3 by the action of:

Oxygen released from the plants, floats upwards into the atmosphere and is converted into ozone by ultraviolet radiations. Formation of ozone thus blocks ultraviolet radiations from reaching the earth surface

More from this chapter

All 163 →
57

The ten per cent law is associated with

 58

The harmful chemical which is accumulating in human beings through food chain is:

 60

Which of the following cannot be added in a composting pit to prepare compost?

 61

The gas A is used by most of the animals to obtain energy from food by the process of respiration. When A is acted upon by radiation X, it gets converted into another gas B which is an allotrope of A but poisonous when inhaled. B forms a kind of layer C in the upper atmosphere which absorbs radiations X coming from a source Y and prevents them from reaching the earth. Some chemicals Z released from the various devices on the earth are destroying the layer C slowly. In fact, a hole has already been formed in layer Cover the area D of the earth.

(a) What are gases?


(i) A, and


(ii) B? Write their molecular formulae.


(b) Name the layer C.


(c) What are (i) X, (ii) Y, and (iii) Z?


(d) Name the area D.


(e) Name any two human ailments which may be caused by X.