Final answer:
Breaking glass is a physical change because it alters the shape of the glass but does not change its chemical structure. The identity of the glass stays the same, distinguishing it from a chemical change, where the substance's chemical identity is transformed.
Step-by-step explanation:
A physical change involves a change in the form or physical properties of a substance without altering its chemical composition. Breaking glass is indeed a physical change because it results in the glass changing shape, physically breaking into smaller pieces, but maintaining the same chemical structure.
The identity of the glass remains the same because no chemical bonds are broken or formed during the process. Examples of physical changes include the melting of ice, where water changes from solid to liquid form while remaining H2O, or sorting a mixture of pennies and nickels, where no change in the material's chemistry occurs.
In contrast, a chemical change involves a change in the substance's chemical identity, such as when gasoline burns or milk turns sour, resulting in new chemical products.