Question

double covalent bond

Answer 1

when 2 atoms of same element share 2 pairs of electrons it is said as double covalent bond.
example is oxygen.
oxygen needs 2 electrons to attain octet structure.
so when 2 atoms of oxygen share 2 pairs of electrons,they attain noble configuration.
hope it helps u

Answer 2

covalent bonds are those bonds which formed by the equal sharing between two atoms
like in Cl2 ,O2 etc
and double covalent bond are formed by the equal sharing of two electrons like in O2