Question

which of these are examples of physical changes? check all that apply.
burning wood
freezing water
cutting paper
iron rusting
mixing water and acetone
done

Explanation:

A physical change is a change in which no new substance is formed, and the substance's chemical composition remains the same.

• Burning wood: This is a chemical change (combustion, new substances like ash and gases are formed).
• Freezing water: Water (liquid) turns to ice (solid) — no new substance, just a state change (physical change).
• Cutting paper: The paper is just divided into smaller pieces, no new substance (physical change).
• Iron rusting: Rust (iron oxide) is a new substance, so it's a chemical change.
• Mixing water and acetone: They mix (forming a solution), but no new substance is created (physical change, as it's a mixture and can be separated, and the chemical identity of water and acetone remains).

So the physical changes are freezing water, cutting paper, and mixing water and acetone.

Answer:

• freezing water
• cutting paper
• mixing water and acetone