* Change in chemical composition: When you boil carrots, the heat causes the water molecules within the carrots to vibrate faster, breaking down the complex carbohydrates (starch) into simpler sugars. This change in chemical composition is irreversible.

* Change in properties: The boiled carrots become softer, their color changes, and they develop a different flavor. These are all indications of a chemical change.

* Formation of new substances: Boiling carrots can also lead to the formation of new substances, like Maillard reaction products which contribute to their browning and flavor.

In contrast, a physical change would involve a change in appearance or state of matter without altering the chemical composition. For example, chopping a carrot is a physical change.