Question

which of the following represents a molecule?
○ a. o₂
○ b. he
○ c. na
○ d. c

Explanation:

A molecule is a group of two or more atoms held together by chemical bonds. \( O_2 \) consists of two oxygen atoms bonded together, so it is a molecule. He (helium), Na (sodium), and C (carbon) are single atoms (monatomic) and do not represent molecules in the context of this question (He is a monatomic gas, Na is a metal atom, C is a single carbon atom like in graphite or diamond lattice but as a single atom representation here).

Answer:

A. \( O_2 \)