Question

The mineral sample did not scratch the glass plate, and the fingernail did not scratch the sample. If the hardness of the glass plate is about 5.5 and the hardness of a fingernail is 2.5, which of the following best describes the mineral's hardness estimate?

a) Hardness greater than 5.5
b) Hardness between 2.5 and 5.5
c) Hardness less than 2.5
d) Impossible to determine

Answer 1

The mineral's estimated hardness is between 2.5 and 5.5 since it did not scratch a glass plate but was not scratched by a fingernail.

Step-by-step explanation:

The hardness of a mineral sample can be estimated using Mohs' scale of mineral hardness, which ranks minerals based on their ability to resist scratching. In this case, since the mineral did not scratch a glass plate with a hardness of approximately 5.5 and was not scratched by a fingernail with a hardness of 2.5, we can deduce that the mineral's hardness is between those two values. Therefore, the best description of the mineral's hardness estimate is that it is harder than a fingernail but softer than glass, which corresponds to option b) Hardness between 2.5 and 5.5.