1. Bonding in Carbon

CHAPTER - 4

COMPOUND AND ITS CARBON

Carbon:-  (i)Most carbon compounds are poor conductors of electricity. Therefore, the bonding in these componds does not give rise to any ions

1. They have low melting and boiling points as compared to ionic compounds
2. Forces of attraction between the molecules are not very strong.
3. The atomic number of carbonis
4. It has four elements I its outermost shell and needs to gain or lose four electrons to attain noble gas configuration.

If carbon were to gain lose electrons:-

• It  could gain four electrons forming C^4-  anion. But it would be difficult for the nucleus with six protons to hold on to ten electrons.
• It could lose four electrons forming C⁴⁺ cation. But it would require a large amount of energy to remove electrons. Carbon overcomes this problem by sharing its valences electrons with other of carbon or with atoms of other elements.

 Bonding in carbon

 Carbon form covalent bounds.  

• Covalent bound formation involves sharing of electrons between bonding atoms which may be either same or different.
• The number of lectrons contributed by an atom for sharing is known as its covalency.

       For example 

1. Molecule of hydrogen  

   

2. Molecule of oxygen

3. Molecule of Nitrogen

4. Structure of methane

Methane CH₄  is widely used as a fixed and is a major component of bio-gas and compressed natural gas ( CNG) .

• CHARACTERISTICS OF COVALENT COMPOUND :-

1. These compounds are molecula in nature  i.e. , they exist as single molecules)
2. These are insoluble in water and soluble in benzene , kerosence and petrol etc.
3. These compounds are poor conductor of electricity.

Allotropes of carbon

  The property due to which an element exists intwo or more forms, which differ in their physical and chemical properties is known as ‘Allotropes’ and the various forms are called “Allotropes”.

• carbon exists in two allotropic  form
• (i) crystalline                 (ii)  amorphous.

The crystalline forms are diamond and graphite the amorphous forms are coat , characol etc.

• In diamound , each carbon is bonded to for other carbon atoms forming rigid 3-D dtructure. Diamond is the nardest substance. * in graphite each carbon is bonded to three other carbon atom. Graphite structure is formed by the hexagonal arrays. Graphite is smooth and slippery . it is very good conductor of electricity.
• Fullerenes form another class of carbon allotropes. The first one to be identified was C-60, which has carbon atoms arranged in the shape of a football.