Question

What do these two changes have in common? Select all that apply. rust forming on a metal gate snails growing shells (1 point) Responses Both are chemical changes Both are chemical changes Both are changes in state Both are changes in state Both are only physical changes Both are only physical changes Both conserve mass

Answer 1

The two changes, rust forming on a metal gate and snails growing shells, have the following in common:

• Both are chemical changes: Rust formation involves a chemical reaction (oxidation) where the metal reacts with oxygen and moisture, resulting in a new substance (rust). Snails growing shells involves biological processes that also involve chemical changes in the materials being deposited to form the shell.

So, you would select "Both are chemical changes."

The other options do not apply:

• They are not changes in state (which typically refer to transitions between solid, liquid, and gas).
• They are not only physical changes, as both involve chemical processes.
• Mass conservation applies to chemical and physical changes in general but is not a common characteristic specific to these two changes.

Given these points, the only applicable response is: "Both are chemical changes."