Which observation most likely indicates that only a chemical change has taken place?(1 point) Responses A reaction occurs. A reaction occurs. States of matter changes. States of matter changes. 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.

This is because a chemical change typically involves a reaction that produces new substances, while changes in states of matter or shape could indicate physical changes.