Page 67 - NCERT Science Class 10 English Medium

4.2 VERSATILE NATURE OF CARBON

We have seen the formation of covalent bonds by the sharing of
electrons in various elements and compounds. We have also seen the
structure of a simple carbon compound, methane. In the beginning
of the Chapter, we saw how many things we use contain carbon. In
fact, we ourselves are made up of carbon compounds. The numbers
of carbon compounds whose formulae are known to chemists was
recently estimated to be in millions! This outnumbers by a large
margin the compounds formed by all the other elements put together.
Why is it that this property is seen in carbon and no other element?
The nature of the covalent bond enables carbon to form a large number
of compounds. Two factors noticed in the case of carbon are –
(i) Carbon has the unique ability to form bonds with other atoms of
carbon, giving rise to large molecules. This property is called
catenation. These compounds may have long chains of carbon,
branched chains of carbon or even carbon atoms arranged in rings.
In addition, carbon atoms may be linked by single, double or triple
bonds. Compounds of carbon, which are linked by only single
bonds between the carbon atoms are called saturated compounds.
Compounds of carbon having double or triple bonds between their
carbon atoms are called unsaturated compounds.
No other element exhibits the property of catenation to the extent
seen in carbon compounds. Silicon forms compounds with
hydrogen which have chains of upto seven or eight atoms, but these
compounds are very reactive. The carbon-carbon bond is very strong
and hence stable. This gives us the large number of compounds
with many carbon atoms linked to each other.
(ii) Since carbon has a valency of four, it is capable of bonding with
four other atoms of carbon or atoms of some other mono-valent
element. Compounds of carbon are formed with oxygen, hydrogen,
nitrogen, sulphur, chlorine and many other elements giving rise to
compounds with specific properties which depend on the elements
other than carbon present in the molecule.
Again the bonds that carbon forms with most other elements are
very strong making these compounds exceptionally stable. One
reason for the formation of strong bonds by carbon is its small size.
This enables the nucleus to hold on to the shared pairs of electrons
strongly. The bonds formed by elements having bigger atoms are
much weaker.

62 Science

2024-25