Why is the valency of oxygen 2 instead of 6?

Answer 1

The valency of an element indicates the way it will react in a chemical reaction. For example, oxygen has six outer electrons and only needs eight electrons to have a complete outer shell. It can either lose six electrons or gain two electrons. It is easier for an oxygen atom to gain two more electrons and therefore its valency is 2.

Answer 2

Oxygen typically forms covalent bonds where it gains two electrons to achieve a stable electron configuration with 8 electrons in its outer shell (octet rule). This leads to an oxidation state of -2, giving it a valency of 2. Although oxygen can form multiple bonds in certain compounds, its common valency is 2 due to its preference for forming stable molecules through sharing two electrons.