Question

a metal is added to a liquid and bubbles form. what might be concluded?
a chemical reaction occurred.
a physical change occurred.
both a chemical and physical change occurred.

Explanation:

When a metal is added to a liquid and bubbles form, it indicates the production of a gas. Gas production is a sign of a chemical reaction. A physical change does not produce a new substance. Since only a chemical reaction is indicated here (bubbles = new gas substance formed), we can conclude.

Answer:

A. A chemical reaction occurred.