Question

: What is valency? Write the valency of hydrogen?

Answer 1

Hint: Atoms join together with chemical bonds by sharing electrons. This is based on how many electrons a given element has filled its electron clouds.

Complete step by step answer:
-We know that atoms are made of electrons, protons, and neutrons. Protons and neutrons make up the nucleus. Electrons are outside the nucleus and responsible for bonding. Valency describes the number of electrons an atom needs to share, gain, or lose to form a bond.
Atoms join together with chemical bonds by sharing electrons. This is based on how many electrons a given element has filled its electron clouds.

-The Hydrogen atom is unique because it has only two spots in its outermost electron level. The valence number of Hydrogen is one because it has only one valence electron. It needs only one shared electron to fill its energy levels.

Note:
We know that in other compounds the outermost level has eight potential electrons, but when all eight electrons are present, the resulting chemical is an inert, noble gas. Atoms having less than eight electrons in the outermost shells will bond with other atoms to share electrons to make eight.
We can think of the fluorine atom with seven valence electrons. It wants to share one electron from another atom to make eight valence electrons.