Question

water should not be left open and stagnant in a place beacuse microorganisms may grow in it . if it is not possible to remove water from that place, oil can be poured over it . can you think ofreason for this?

Answer 1

Water in an open place or stagnant in an area will increase the chance of microorganisms to grow through it.

To avoid the growth of the microorganisms, oil is poured into the water, and because of the light nature of oil, it forms a layer over the water which restricts the microorganisms to develop in it.

Answer 2

If water is left open and stagnant in a place microorganisms grow.

To avoid the growth of microorganism, oil is poured into the water and because of the light nature of oil, it forms a layer over water which restricts the microorganism to develop in it and hence growth of microorganisms are blocked.