Question

each of the following are examples of chemical reactions, except ___.
a dissolving sugar in water to make lemonade
b food rotting
c rust forming on your bicycle
d photosynthesis

Explanation:

• Option A: Dissolving sugar in water is a physical change. The sugar molecules disperse in water but no new substance is formed.
• Option B: Food rotting is a chemical reaction. Microorganisms break down food substances, forming new substances (e.g., foul - smelling compounds).
• Option C: Rust forming on a bicycle is a chemical reaction. Iron reacts with oxygen and water to form iron oxide (rust), a new substance.
• Option D: Photosynthesis is a chemical reaction. Plants convert carbon dioxide and water into glucose and oxygen using sunlight, forming new substances.

Answer:

A. dissolving sugar in water to make lemonade