Question

The most common oxidation state of an element is -2. The number of electrons present in its outermost shell is:

Answer 1

The most common oxidation state of the element is -2. This means that it has a very high tendency to gain 2 electrons in order to attain the nearest noble gas configuration.
So, it has 2 electrons less than 8. Therefore, it has 6 electrons in its outermost shell.
Hence Oxygen has 6 electrons in the outer most shell and shows common oxidation state −2