How many electrons are shared in the lewis structure of ch2cl2?

Eight electrons are shared.

Explanation:

The total valence electrons available in the given compound are:

4 from carbon

seven each from two chlorine atoms

one each from hydrogen atom

Total = 4 +2 + 14 = 20 electrons

Out of these 20 eight will  be involved in making four bonds as:

a) two separate bonds with two chlorine atoms and carbon

b) two separate bond with two hydrogen atoms and carbon

In each bond two electrons are shared.

Total electrons shared = 8.

Rest electrons will be lone electrons on chlroine atoms (six on each atom).