Question

drag the missing word into place a(n) of carbon dioxide contains one carbon atom and two oxygen atoms. neutron electron molecule

Explanation:

To solve this, we analyze the options:

• A neutron is a subatomic particle in an atom's nucleus, not related to the composition of carbon dioxide (which is a compound made of atoms).
• An electron is also a subatomic particle, involved in atomic structure but not the unit of a compound like carbon dioxide.
• A molecule is a group of atoms bonded together. Carbon dioxide ($\ce{CO_2}$) is made of one carbon atom and two oxygen atoms bonded, so a molecule of carbon dioxide has this composition.

Answer:

molecule