<span> Geographical</span> isolation refers to a
population of organisms (such as plants and animals) that are separated
from other species, thus unable to exchange genetic material with other
organisms because of physical boundaries that isolate them or any
unfavorable circumstances that prevent interbreeding.
It can become an ion because it can lose or gain an electron. It can become a part of molecule because it can form covalent bond with other atoms to gain a full valence shell.
