Question

1. describe phase changes such as melting, freezing, vaporization, condensation.
2. what is the law of conservation of mass, and how does it apply to chemical reactions?

Explanation:

Question 7:

Melting is the change from solid to liquid (e.g., ice to water). Freezing is liquid to solid (e.g., water to ice). Vaporization is liquid to gas (e.g., water boiling to steam). Condensation is gas to liquid (e.g., steam on a cold surface).

Question 8:

The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. In chemical reactions, the total mass of reactants equals the total mass of products. For example, in \(2H_2 + O_2
ightarrow 2H_2O\), the mass of hydrogen and oxygen (reactants) is the same as the mass of water (product).

Answer:

Question 7:

Melting: solid to liquid. Freezing: liquid to solid. Vaporization: liquid to gas. Condensation: gas to liquid.

Question 8:

Law of Conservation of Mass: mass is conserved. In chemical reactions, mass of reactants = mass of products.