Question

Can someone make me understand the covalent bonding of CO2

Answer 1

Carbon has 4 valance electrons(e-) : :Oxygen has 6 valance electrons(e-).
Carbon wants to complete its octet : : Oxygen wants to complete its octet.
so carbon and both oxygens simultaneously share 2 electrons so carbon shares 2 electrons from each oxygen + the ones it already had. 2(2)+4 i.e 8
                                                   . .       . .
                                                  :O=C=O:

Answer 2

All the atoms need 8 valence electrons (electrons in the last shell) in order to attain stability. In the case of carbon, there are 4 valence electrons which means it needs 4 more to attain stability. It cannot give or take electrons so it has to share with other atoms. As two pairs of electrons are shared between carbon and oxygen, there is a double covalent bond. (O=C=O)