Physical vs. Chemical Change Quick Check

Question

1 of 41 of 4 Items
Question
Which observation most likely indicates that only a chemical change has taken place?(1 point)
Responses

States of matter changes.
States of matter changes.

A reaction occurs.
A reaction occurs.

The shape changes.
The shape changes.

The change cannot be reversed.

Answer 1

The observation that most likely indicates that only a chemical change has taken place is:

A reaction occurs.

Chemical changes are typically marked by the formation of new substances, which is indicated by a reaction occurring. The other options may relate to physical changes, where substances change form but do not become something new.