Question

1. do you think dissolving salt in water is a chemical change or a physical change? why?

Explanation:

To determine if dissolving salt (sodium chloride, \(NaCl\)) in water is a chemical or physical change, we analyze the nature of the process:

1. Physical Change Definition: A change where no new substance is formed, and the original substance can be recovered (e.g., via evaporation for saltwater).
2. Dissolving Salt in Water: When \(NaCl\) dissolves, it dissociates into \(Na^+\) and \(Cl^-\) ions, but these ions are still \(Na^+\) and \(Cl^-\) (no new chemical bonds or substances are created). The salt can be reclaimed by evaporating the water, confirming the change is reversible and no new substance is formed.

Answer:

Dissolving salt in water is a physical change because no new substance is formed (the salt ions remain chemically unchanged, and the salt can be recovered by evaporating the water), and the change is reversible.