Question

why is carbon considered tetravalent

Answer 1

It has four unpaired valence electrons - hence "tetravalent"

Answer 2

I think that explanation could more misguiding than helpful. Take as nitrogen as an example what valance is that?

Answer 3

You're quite right - tetravalent refers to the fact that carbon can form four bonds BECAUSE it has four unpaired electrons.

SImply put, tetravalent refers to how many covalent bonds can be formed, which depends on how many unpaired electrons you have.

Answer 4

Exactly! :) I thought that with the first explanation you might think that nitrogen was pentavalent instead of trivalent.