Which observation most likely indicates that only a chemical change has taken place? (1 point)

Question

A reaction occurs.

The change cannot be reversed.

The shape changes.

O States of matter changes.

Answer 1

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

The change cannot be reversed.

Chemical changes often result in the formation of new substances, which are typically not easily reversible, unlike physical changes where the original substance can often be recovered.