Which statement about emulsification is true?

• A. Emulsification is a chemical change
• B. Emulsification is a physical change
• C. Bile is an enzyme
• D. Emulsification is both chemical and physical

Answer: (B)

Emulsification is the physical process of breaking up large fat globules into tiny droplets so they can mix in the watery digestive fluids. This happens when bile salts act as emulsifiers, stabilizing the fat droplets in the chyme. Since the fats’ chemical structure isn’t changed during this process—no bonds are broken or new molecules formed—it's a physical change. After emulsification, enzymes like pancreatic lipase chemically hydrolyze the fats, but that reaction is separate from emulsification itself. Bile is not an enzyme, and emulsification isn’t a chemical reaction, so the statement that emulsification is a physical change is the best choice.