Question

define valency and write significance of molecular formula

Answer 1

The number of electrons that an atom can lose Gain or share during a chemical reaction is called its valency.
significance of molecular formula
1)both the molecules and the molecular mass of the compound.
2) the respective number of different atoms present in 1 molecule of the compound.
3) the ratio of the respective masses of the elements present in the compound

Answer 2

Valency is the combining capacity of element.
So element having 1,2,3... valency will gain some electron or lose some electron to form the ionic bonds.
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