Question

A solution of salt water is boiled. The water evaporates and solid salt remains. Which statement is true?
A.
The salt and the water have both undergone chemical changes.
B.
The salt has undergone a physical change, and the water has undergone a chemical change.
C.
The salt and the water have both undergone physical changes.
D.
The salt has undergone a chemical change, and the water has undergone a physical change.

Answer 1

C because neither the water or salt have changed their molecular structure. H2O is still H2O and NaCl is still NaCl.

Answer 2

Answer:

The salt and the water have both undergone physical changes.

Explanation:

A physical change occurs when the appearance of a substance changes, but its chemical identity does not. In this case, the water has changed its appearance by changing from a liquid to a gas, while the salt has changed its appearance by changing from a dissolved substance to a solid. However, no chemical reactions have taken place and so only physical changes have occurred.