Question

Arrange the following substances in the increasing order of hardness.

• A. Sponge
• B. Iron rod
• C. Brick
• D. Diamond

Answer 1

Materials that are not easy to compress are called hard substances. Hardness is the ability of a substance to withstand the pressure applied to deform it.
Depending on the ease of compressibility of an item or its ability to withstand the pressure applied, the order of hardness would be:
Sponge < Brick < Iron Rod < Diamond