Question

What is the total number of electrons shared in the bonds between the two carbon atoms in a molecule of `H-C=C-H`?

Answer 1

In acetylene, `HC-=CH`, or ethylene, `H_2C=CH_2`?

Explanation:

Each carbon atom has 4 valence electrons. In acetylene, there are 3 carbon-carbon bonds, i.e. 6 electrons shared between the carbons. And in ethylene there are 4 electrons shared between the carbon atoms; the remaining 2 electrons constitute half of the `C-H` bonds.