Question

1. physical change: 2. distillation: 3. chemical property: 4. chemical change: 5. law of conservation of mass: questions: 1. distinguish a solution from a mixture. give two examples of each 2. explain why evaporation is a physical change and not a chemical change. then give an example of something going through a chemical change.

Explanation:

1. A mixture is a combination of two or more substances that are not chemically combined and can be separated by physical means. A solution is a homogeneous mixture where one substance (solute) is dissolved in another (solvent) at a molecular - level. Examples of mixtures: a mixture of sand and water, a salad. Examples of solutions: salt - water (sodium chloride dissolved in water), sugar - water (sucrose dissolved in water).
2. Evaporation is a physical change because it involves a change in the state of matter (from liquid to gas) without changing the chemical composition of the substance. For example, when water evaporates, it is still water (H₂O) in the gaseous state. An example of a chemical change is the rusting of iron. Iron (Fe) reacts with oxygen (O₂) and water (H₂O) in the air to form iron oxide (rust, Fe₂O₃·xH₂O), which is a new substance with different chemical properties.

Answer:

1. A mixture is a combination of substances not chemically combined, e.g., sand - water, salad. A solution is a homogeneous mixture with solute dissolved in solvent, e.g., salt - water, sugar - water.
2. Evaporation is physical as it's a state - change without chemical composition change. Example of chemical change: rusting of iron.