Which statement best explains why carbon bonds to four hydrogen atoms to form methane but to only two oxygen atoms to form carbon dioxide?

Question

A. The carbon in carbon dioxide is stable, with fewer valence electrons than the carbon in methane.
B. The carbon in methane has more valence electrons to share than the carbon in carbon dioxide
C. Hydrogen shares one valence electron with carbon, and oxygen shares two valence electrons
D. Hydrogen shares electrons with carbon, but oxygen transfers its electrons

Answer 1

The statement that best explains why carbon bonds to four hydrogen atoms to form methane but to only two oxygen atoms to form carbon dioxide is:

C. Hydrogen shares one valence electron with carbon, and oxygen shares two valence electrons.

This is because carbon needs four electrons to complete its octet, and it can obtain these by forming four single covalent bonds with hydrogen (which each provide one electron). In the case of oxygen, each oxygen atom can form a double bond with carbon (sharing two pairs of electrons), allowing carbon to complete its octet with only two oxygen atoms.