Question

explane all things about valency

Answer 1

the valence or valency of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules. The concept of valencedeveloped in the second half of the 19th century and helped successfullyexplain the molecular structure of inorganic and organic compounds.

Answer 2

Valency refers to the ability of an atom or a group of chemically bonded atoms to form chemical bonds with other atoms or groups of atoms. The valency of an element is determined by the number of outer shell (valence) electrons. The valency of polyatomic ions (such as SO42- ) is the charge on the ion.