Page 82 - NCERT Science Class 10 English Medium

What you have learnt

n Carbon is a versatile element that forms the basis for all living organisms and many
of the things we use.

n This large variety of compounds is formed by carbon because of its tetravalency
and the property of catenation that it exhibits.
n Covalent bonds are formed by the sharing of electrons between two atoms so that
both can achieve a completely filled outermost shell.
n Carbon forms covalent bonds with itself and other elements such as hydrogen,
oxygen, sulphur, nitrogen and chlorine.
n Carbon also forms compounds containing double and triple bonds between carbon
atoms. These carbon chains may be in the form of straight chains, branched chains
or rings.
n The ability of carbon to form chains gives rise to a homologous series of compounds
in which the same functional group is attached to carbon chains of different lengths.

n The functional groups such as alcohols, aldehydes, ketones and carboxylic acids
bestow characteristic properties to the carbon compounds that contain them.
n Carbon and its compounds are some of our major sources of fuels.
n Ethanol and ethanoic acid are carbon compounds of importance in our daily lives.
n The action of soaps and detergents is based on the presence of both hydrophobic
and hydrophilic groups in the molecule and this helps to emulsify the oily dirt and
hence its removal.

E X E R C I S E S

1. Ethane, with the molecular formula C H has
2 6
(a) 6 covalent bonds.
(b) 7 covalent bonds.
(c) 8 covalent bonds.
(d) 9 covalent bonds.
2. Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.
3. While cooking, if the bottom of the vessel is getting blackened on the outside,
it means that
(a) the food is not cooked completely.
(b) the fuel is not burning completely.
(c) the fuel is wet.
(d) the fuel is burning completely.

Carbon and its Compounds 77

2024-25