CHAPTER – 4
CARBON AND ITS COMPOUNDS
Carbon is a versatile element. In earth’s crust, carbon is 0.02% and found in form of
minerals. Atmosphere has 0.03% of Carbon dioxide. All living structures are carbon
based. Covalent Bond in Carbon – The atomic number of carbon is 6 and its electronic
configuration is 2, 4. To attain a noble gas configuration it can 1. Gain 4 electrons. But
it would be difficult for nucleus to hold 4 extra electrons. 2. Lose 4 electrons. But it
would require a large amount of energy to remove 4 electrons. – It is difficult thus for
an atom of carbon to either gain or lose electrons. – Carbon attains the noble gas
configuration by sharing its valence electrons with other atoms. Atoms of other
elements like hydrogen, oxygen, nitrogen, chlorine also show sharing of valence
electrons. – Formation of H2 , O2 and N2 is shown as below : AK 32 X – Science – It is
evident that the number of shared pair of electrons can be one, two or three. Try
making the structures of H2O and CH4 . – Bond formed by the sharing of an electron
pair between two atoms is called covalent bond. – Covalently bonded molecules have low
melting and boiling points because of comparatively weaker intermolecular forces,
unlike ionic compounds.
CARBON AND ITS COMPOUNDS
Carbon is a versatile element. In earth’s crust, carbon is 0.02% and found in form of
minerals. Atmosphere has 0.03% of Carbon dioxide. All living structures are carbon
based. Covalent Bond in Carbon – The atomic number of carbon is 6 and its electronic
configuration is 2, 4. To attain a noble gas configuration it can 1. Gain 4 electrons. But
it would be difficult for nucleus to hold 4 extra electrons. 2. Lose 4 electrons. But it
would require a large amount of energy to remove 4 electrons. – It is difficult thus for
an atom of carbon to either gain or lose electrons. – Carbon attains the noble gas
configuration by sharing its valence electrons with other atoms. Atoms of other
elements like hydrogen, oxygen, nitrogen, chlorine also show sharing of valence
electrons. – Formation of H2 , O2 and N2 is shown as below : AK 32 X – Science – It is
evident that the number of shared pair of electrons can be one, two or three. Try
making the structures of H2O and CH4 . – Bond formed by the sharing of an electron
pair between two atoms is called covalent bond. – Covalently bonded molecules have low
melting and boiling points because of comparatively weaker intermolecular forces,
unlike ionic compounds.
