In colloquial speech, speed of sound refers to the speed of sound waves in air. However, the speed of sound varies from substance to substance: typically, sound travels most slowly in gases, faster in liquids, and fastest in solids.

The egg of a hen is A Single Cell structure inside the shell before the fertilization but after fertilization, the cells fused and divide into two cells inside the shell. The shape of an egg is the same as a prolate spheroid with one end larger than the other and has cylindrical symmetry along the long axis. An egg is surrounded by a thin, hard shell and the thin membranes exist inside the shell. The egg yolk is hung in the egg white by one or two spiral bands of tissue known as chalazae.