Question

Why methene does not exists, as it is possible that hydrogen can share two pairs of electrons with carbon twice.

Answer 1

1. The alkene formation is due to the formation of double bond between two consecutive carbon atoms.

2. But in methane, there is only one carbon atom in the molecule. And as for H, it has only one electron to form bond, so H cannot form a double bond.

3. So, no scope for a -C=C-, thus methene does not exist.