The best statement that describes the substances N₂ and NO₂ is: Both are molecules. NO₂ is also a compound.
Here's the reasoning:
- N₂ (nitrogen gas) is a molecule made up of two nitrogen atoms, and it is considered an element because it consists of only one type of atom.
- NO₂ (nitrogen dioxide) is a molecule that consists of nitrogen and oxygen atoms, and it is classified as a compound because it is made up of more than one type of element.
Thus, the correct response should acknowledge that N₂ is an element (specifically a diatomic molecule), while NO₂ is a compound that is also a molecule.