A glass window is hard to scratch with a coin, but it can shatter when a baseball hits it. Which statement is correct?
AGlass is both hard and strong
BGlass is hard (scratch-resistant) but not very strong (it breaks under impact)
CGlass is strong but not hard
DGlass is neither hard nor strong — it is just fragile
Glass is hard — its surface resists scratching from most everyday objects. But glass is not very strong against impact — a sudden force can shatter it. This shows that hardness and strength are different properties. A material can be very good at one and poor at the other.
Question 2 True / False
The hardest material is typically the strongest material.
TTrue
FFalse
Answer: False
False. Hardness and strength measure different things. Diamond is the hardest natural material — nothing scratches it — but it can crack or shatter if you hit it with a hammer. Steel is not as hard as diamond (steel can be scratched), but steel is extremely strong and resists breaking under heavy loads.
Question 3 Short Answer
What is the difference between hardness and strength?
Think about your answer, then reveal below.
Model answer: Hardness is how well a material resists being scratched or dented. Strength is how well a material resists being broken, bent, or pulled apart. A material can be hard without being strong, or strong without being hard.
Think of it this way: hardness is about the surface (can you scratch it?), while strength is about the whole object (can you break it?). Glass has a hard surface but breaks easily. Rope is soft (easy to dent) but incredibly strong (hard to snap).