CBSE Class 10 Answered

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 C^4-, 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.