Give reasons for the following:
(a)A sponge is a solid but can be easily compressed.
(b)Smell of perfume travels a few yards away.
(a) A sponge has minute holes, in which air is trapped. When we press it, air is expelled out from the holes and it can be compressed.
(b)The molecules in a gas are arranged far away from each other. A gas has a tendency to occupy the entire space available to it and its molecules are always in random motion. Due to high speed of particles and large space between them, gases show the property of diffusing very fast into other gases. So, the smell of perfume is carried a few yards away.