Carbon

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The symbol for carbon is C. The atomic number of carbon is 6. Its electronic configuration is 2, 4. It requires 4 electrons to achieve the inert gas electronic configuration.

It could gain four electrons forming C4- cation. But it would be difficult for the nucleus with six protons to hold on to ten electrons.

It could lose four electrons forming C4+ cations. But it requires a large amount of energy to remove four electrons.

So it doesn't form ionic bond.

Thus, carbon share its valence electrons with other carbon atoms or with atoms of other elements.

The atoms of other elements hydrogen, oxygen, nitrogen, chlorine also form bond by sharing of electrons.

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Versatile Nature of Carbon: 

Carbon shows  two main properties which makes carbon to form large number of compounds.

• Catenation
• Tetravalent nature

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(i) Catenation:-  carbon link with carbon atom through covalent bonds to form long straight, branched and rings of different sizes are called Catenation.
Carbon shows this property due to

• Its small size
• great strength of the carbon-carbon bond.

Carbon can also form stable multiple bonds (double or triple) with itself and with the atoms of other elements.

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Straight chain compounds : The compounds which contain straight chain of carbon atoms e.g. normal butane (C₄H₁₀), normal pentane (₅H₁₂) etc.

Branched chain compounds : Those compounds which are branched. e.g. isopentane (C₅H₁₂), neopentane (C₅H₁₂) etc.

Closed chain compounds or Ring compounds :

Cyclic compounds are called closed chain or ring compounds e.g. cyclopentane (C₅H₁₀), cyclobutane (C₄H₈), cyclopropane (C₃H₆) etc.

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(ii) Tetravalent Nature: Carbon has valency of four. It makes bond with four other atoms of carbon or some other atoms like hydrogen, sulphur, chlorine etc.

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