A piece of iron is heated until it glows red and then is allowed to cool down. What does this process represent?

Question

A. A chemical change due to the color change
B. A physical change because no new substances formed
C. Both a chemical and physical change
D. A change in state from a solid to a liquid

Answer 1

The correct answer is: B. A physical change because no new substances formed.

When iron is heated until it glows red, it undergoes a physical change; its temperature increases and it emits visible light, but its chemical composition remains the same. When it cools down, it simply returns to its original state without creating new substances. Therefore, option B is the most accurate description of the process.