Question

hematite is a naturally occurring mineral and a common form of iron ore. the following statements describe physical and chemical changes occurring to hematite. which statement describes a chemical change?
a. the hematite particles separate from each other but remain the same substance
b. the hematite particles rearrange to form a new substance.
c. the hematite particles are mixed with particles of a different substance.
d. the hematite particles vibrate more quickly when they are heated
e. the hematite particles are moved from one location to another location

Explanation:

To determine a chemical change, we recall that a chemical change involves the formation of a new substance, while a physical change does not.

• Option A: Particles separating but remaining the same substance is a physical change (e.g., separation in a mixture, no new substance).
• Option B: Rearranging to form a new substance means a chemical reaction occurred, so this is a chemical change.
• Option C: Mixing with another substance is a physical change (mixture formation, no new substance).
• Option D: Particles vibrating more (due to heating) is a physical change related to temperature/energy, no new substance.
• Option E: Moving particles to another location is a physical change (change in position, no new substance).

Answer:

B. The hematite particles rearrange to form a new substance.