Question

what is valency? and when will 2 elements on being mixed together from a compound ??​

Answer 1

Answer:

In chemistry, the valence or valency of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules.

Elements can be chemically combined into compounds, therefore, a compound consists of two or more elements combined, in definite proportions, by chemical means. Compounds may be formed by combining atoms of their constituent elements by ionic bonds or by covalent bonds.

Answer 2

The no. Of electrons that needs to be given out or taken in is called valency.
When two elects needs to become stable , it shares or donates and accept electrons to form compounds so that it become stable like noble gases