which must be a mixture of substances? 1. solid

Question

2. liquid
3. gas
4. solution

Answer 1

4 is the answer

Answer 2

Solids may be a mixture but they may also be a pure substance. example salt

Liquids may be a mixture but they may also be a pure substance. example water.

Gases may be a mixture but they may also be a pure substance. example oxygen.

Solutions are solutes dissolved in solvents; therefore, these MUST be a mixture.