Question

which of these chemical formulas - kcl, xe, co₂, h₂ - represents both an element and a molecule?

○ h₂

○ kcl

○ co₂

○ xe

Explanation:

An element is a pure substance with one type of atom; a molecule is a group of atoms bonded together. $\text{KCl}$ is an ionic compound (not a molecule or element). $\text{CO}_2$ is a molecule but a compound (two elements). $\text{Xe}$ is a noble gas element, but it exists as single atoms (not a molecule). $\text{H}_2$ is a diatomic molecule made of hydrogen atoms, so it is both an element and a molecule.

Answer:

H₂