Question

dianne observes her science teacher testing a sample of an unknown substance. she recorded her observations in the table below
which test would provide evidence of a chemical change?
1 melts when heated
2 breaks into smaller pieces
3 dissolves in water
4 reacts with vinegar
yes
no

Explanation:

Step1: Recall chemical change definition

A chemical change produces new substances.

Step2: Analyze each test

• Test 1 (melts when heated): Physical change (change of state).
• Test 2 (breaks into smaller pieces): Physical change (change of form).
• Test 3 (dissolves in water): Physical change (mixture formation).
• Test 4 (reacts with vinegar): Produces new substances (chemical change).

Answer:

4