Question

why valency of oxygen is 2

Answer 1

AS OXYGEN HAS 8 ELECTRONS 2 ELECTRONS IN 1st SHELL AND 6 ELECTRONS IN OUTERMOST SHELL . TO OBTAIN STABLE CONFIGURATION IT NEEDS 2 ELECTRONS WHICH GIVES VALENCY AS 2.

Answer 2

Friend , valency of oxygen is not 2. Its atomic no is 8. So its total electrones are 8. Now 2 electrones fill first shell and then in second shell only 6 electrones are left and So is its valency.