Question 2
A carbon atom has the configuration 2, 4. How many covalent bonds does it form in methane?
The right answer is the one marked above.
Four. Carbon has four valence electrons and needs four more to reach eight, so it forms four bonds — one to each of four hydrogen atoms.
Two and six do not match the gap between four and eight. Eight is the number of electrons carbon finishes with, not the number of bonds; each bond supplies two electrons, so eight electrons means four bonds.