Question

1. which is an example of a physical change? (1pts)

□ steam from the boiling water condenses on the cooler part of the ceiling.
□ the crude metal ore was first heated then combined with pure oxygen gas to make the oxide of the metal.
□ the chef made scrambled eggs for their breakfast.
□ a piece of paper burns in air with a smoky flame.
□ the table salt in the warehouse was used to make some of the polymeric material.

Explanation:

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

• Steam condensing is water changing from gas to liquid, no new substance.
• Heating ore with oxygen forms a new metal oxide (chemical change).
• Scrambling eggs denatures proteins, forming new structures (chemical change).
• Burning paper produces new substances like ash and gases (chemical change).
• Using table salt to make polymeric material involves chemical reactions (chemical change).

Answer:

Steam from the boiling water condenses on the cooler part of the ceiling.