How hard is a metal?

The idea

Metals are generally hard, but their hardness varies from metal to metal.

Same push, two metals

Two different metals are pushed with the same hard point and the same force.

What do you expect?

• The dents may be different
• The dents are the same
• Neither metal can be dented

Compare two metals

Press Next step. The metals X and Y in the picture are examples.

Hard, but not equally hard

Metals are generally hard. But the same push can make a small dent in one metal and a bigger dent in another. Hardness varies from metal to metal.

Metals are generally hard, but their hardness varies from metal to metal.

Notes

Metals are generally hard; the hardness varies from metal to metal.

Check yourself

Metals are ...

In the picture, the same push dents metal Y more than metal X. Which is harder?

Does hardness vary from metal to metal?

• equally hard, with no difference between metals. The book says hardness varies from metal to metal.
• generally soft. The book says metals are generally hard.
• generally hard, and hardness varies from metal to metal — correct. Yes!
• Metal X — correct. Yes!
• Metal Y. Metal Y took the bigger dent under the same push, so it is less hard.
• Both are equally hard. The dents are of different sizes, which shows that the hardness is different.
• No, it is the same for every metal. The book says the hardness varies from metal to metal.
• Yes, it varies — correct. Yes!
• Metals have no hardness. The book says metals are generally hard.