Question

how is a chemical change different than a physical change?
in a physical change, a new substance is formed.
all chemical changes are reversible, while physical changes are not.
all physical changes are reversible, while only some chemical changes are reversible.
in a chemical change, a new substance is formed.

Explanation:

In a physical change, the substance's form or state changes, but no new substance is formed. In a chemical change, chemical bonds are broken and new ones are formed, resulting in a new substance. Also, not all physical changes are reversible (e.g., breaking glass), and not all chemical changes are reversible (e.g., burning wood).

Answer:

In a chemical change, a new substance is formed.