Question

Carbon atoms have four electrons in their outer shell. This means that a single carbon atom can form up to _______ bonds with other atoms.
two
eight
four
six

Answer 1

The answer is: four.

For example compound carbon dioxide (CO₂):

Electron configuration of carbon: ₆C 1s² 2s² 2p².  

Electron configuration of oxygen: ₈O 1s² 2s² 2p⁴.

Carbon atom is sp2 hybridized, it has three sp2 orbitals and one p orbital, they form four bonds.

Oxygen has two p orbitals, they form two bonds (one sigma and one pi bond).

p orbitals from carbon and oxygen overlap and form pi bond.

Answer 2

If my memory serves me well, the correct answer looks like this: Carbon atoms have four electrons in their outer shell. This means that a single carbon atom can form up to four bonds with other atoms.