Carbon and its compounds

Class X

Carbon is an element. It is a non-metal. All living thing, plant and animal are made up of carbon. These compounds made up of carbon are called organic compound. From The food substance we eat to the fibre we use all are carbon compounds. The fuels like LPG, kerosene, CNG, coal, petrol all are carbon compound. The various substances surrounding us are made up of carbon like wood, paper, rubber, plastic. So, it is a fact that we are surrounded by carbon and its compound.

Atomic number of carbon is 6. The number of electrons in carbon is 6. There are 2 electrons in the K shell of carbon atom. K shell is the innermost shell of an atom. The remaining 4 electrons are in the outer L shell.

Properties of carbon:

1. Carbon is tetravalent

2. Carbon form covalent bond

3. Carbon posses the property of catenation

4. Carbon burn in air to give carbon dioxide

Tetravalency: The outermost shell of a carbon atom contains 4 electrons. To gain inert gas configuration a carbon atom has to gain four electrons or it has to lose four electrons. Therefore the valency of carbon is 4 and it is called tetravalent.

Covalent bond: due to the tetravalent nature of carbon it is difficult to either remove 4 electrons or to add 4 electrons. Therefore it is obvious that to gain inert gain configuration carbon atom has to share 4 electrons. Since carbon always gain 8-electron configuration by sharing it forms covalent bond.

Catenation: property of carbon to form strong bonds by carbon atoms among themselves and with other elements is called catenation.

Carbon give carbon dioxide on burning: when carbon combines with oxygen it makes carbon dioxide.

Question: why carbon atoms form strong covalent bond?

The reason for formation of strong covalent bonds is the small size of carbon atoms. Due to small size, the nuclei hold the shared electrons for bond strongly, leading to formation of strong covalent bonds. Due to strong bonds these carbon compound they are very stable compounds.

Occurrence of carbon

Carbon occurs in nature in basically two forms:

Elemental form and combined form

Elemental form: the form in which carbon occur in free state that means elemental state. Diamond, graphite and buckminsterfullerene are the three forms that are available in nature

Combined form: carbon occurs in nature in form of compound. When carbon combine with oxygen, hydrogen and other elements present in nature then these are called carbon compound and this is the combined form of carbon. Example are CNG, petrol, coal, wood, carbonates, marble, cotton, grains etc.

Allotropy

The phenomenon in which an element exists in more than one physical form in nature is called allotropy. The various physical forms in which the element is available are called allotropes.

Allotropes of carbon are diamond, graphite, buckminsterfullerene, charcoal(amorphous).

Next Topic Diamond