Question

1. which of the following is an example of a chemical change in digestion? a. teeth grinding food into smaller pieces b. peristalsis in the esophagus that contracts food to the stomach c. digestion in the small intestine d. muscle contractions in the rectum to expel waste

Explanation:

• Option A: Teeth grinding food is physical (size change, no new substance).
• Option B: Peristalsis is muscle movement (physical, no chemical reaction).
• Option C: Small intestine digestion involves enzymes breaking food into new substances (chemical change).
• Option D: Rectum muscle contractions are physical (waste expulsion, no new substance).

Answer:

C. Digestion in the small intestine