Question

why carbon atom cannot loose and gain electron

Answer 1

Elements with four outermost electrons such as carbon find it easier to share electrons than attempt to gain or lose four electrons. The bond formed by sharing of electrons between the two atoms is called covalent bond.

If carbon gains 4 electrons and form C4-

, it would be difficult for the nucleus which has six protons to hold the ten electrons.

Large amount of energy would be required if it loses 4 electrons and forms C4+

leaving behind a cation with six protons in its nucleus and holding just two electrons.

So to avoid this carbon shares its valence electrons with other atoms of carbon or with atoms of other elements.

Answer 2

Carbon is tetravalent ( 4 valency)
* It cannot gain 4 electrons as it would be hard for nucleus with 6 protons to hold on to 4 extra electrons.
* It can't lose 4 electrons due to energy consideration.
As it is very small atom and this would 6 protons holding 2 electrons only.