Question

13 physical and chemical changes occur during digestion. an example of a chemical change during digestion is a the esophagus moving food b stomach acid breaking down food c the mouth swallowing food

Explanation:

To determine the chemical change during digestion, we analyze each option:

• Option A: The esophagus moving food is a physical process (movement, no new substance formed).
• Option B: Stomach acid breaking down food involves chemical reactions (e.g., hydrolysis) that break food into new substances, so this is a chemical change.
• Option C: The mouth swallowing food is a physical action (no chemical reaction, just moving food).

Answer:

B. stomach acid breaking down food