A polyatomic ion that contains two hydrogen atoms is called

a. dihydrogen.

b. bihydrogen.

c. duohydrogen.

d. double-hydrogen.

A polyatomic ion that contains two hydrogen atoms is called a. dihydrogen. It is a rule for non-metallic polyatomic molecules to make use of such prefixes before each element's name. For example, the compound H2S can be called hydrogen sulfide, dihydrogen monosulfide or simply dihydrogen sulfide.