Question

Define valency by taking examples of silicon and oxygen.

Answer 1

Valency refers to the number of electrons obtained, lost, or shared to complete the octet of electrons in the valence shell.

Valency of silicon: It has electronic configuration → 2, 8, 4

Thus, 4 electrons are shared with other atoms to complete the octet, and so its valency = 4.

Valency of oxygen: It has electronic configuration → 2, 6

Thus, It will gain 2 electrons to complete its octet. So its valency = 2.