Water, rust, and salt are atoms. Water, rust, and salt are mixtures. Water, rust, and salt are elements. Water, rust, and salt are compounds.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of the following do water (H2O), rust (Fe2O3), and salt (NaCl) have in common?
Possibilities:
- Water, rust, and salt are atoms.
- Water, rust, and salt are mixtures.
- Water, rust, and salt are elements.
- Water, rust, and salt are compounds.

Water, rust, and salt are compounds.