Question

question 10 (1 point) listen which one of these represents a physical change? a) sugar, when heated, becomes brown b) bleach turns hair yellow c) water, when heated, forms steam d) apples, when exposed to air, turn brown e) milk turns sour

Explanation:

A physical change is a change where no new substance is formed, only the state or form of the substance changes.

• a) Heating sugar to brown it causes caramelization, a chemical change creating new compounds.
• b) Bleach reacting with hair to lighten it involves chemical breakdown of hair pigments, a chemical change.
• c) Water turning to steam is a phase change (liquid to gas); the substance remains H₂O, no new material is made.
• d) Apples browning is oxidation, a chemical reaction that creates new brown-colored compounds.
• e) Milk souring is caused by bacteria fermenting lactose into lactic acid, a chemical change with new substances.

Answer:

c) Water, when heated, forms steam