1. Components retain their individual properties: When salt (NaCl) dissolves in water (H₂O), the salt molecules are dispersed throughout the water, but they don't chemically change. You can still separate the salt from the water by evaporation, proving that the individual components haven't formed a new substance.
2. No fixed ratio: Unlike compounds, where the elements are always present in a fixed ratio, salt water can have varying amounts of salt dissolved in it. You can have a very salty ocean water or a very dilute salt solution, both still considered salt water.
3. Homogenous vs. Heterogeneous: Salt water is considered a homogeneous mixture because the salt and water are evenly distributed throughout. You can't see individual salt crystals. This is different from a heterogeneous mixture like sand and water, where you can easily see the distinct components.
In summary, salt water is a mixture because the components retain their individual properties, the ratio of salt to water is not fixed, and the mixture is homogeneous.
