Why do valency electrons involve in bond formation , than electrons of inner shells ?

What are valence electrons?

Number of valence electrons in carbon is

Number of valence electrons in carbon is

The number of valency electrons in carbon atom (Z=6) is

How do valence electrons are showed in the lewis structure ?

The total number of electrons in the bond formation of Nitrogen molecule

Why do electrons move in specified direction ?

The number of bridge bonds, the maximum number of planar atoms and the number of electrons involved in the formation of bridge bonds in diborane are x, y and z respectively, then (x+y–z) = ?