Question

One student did an experiment with two unknown minerals, Mineral 1 and Mineral 2. The hardness scale shown below was used for the experiment.

Mineral: Talc Gypsum, Calcite, Fluorite, Apatite, and Orthoclase
Hardness: 1, 2, 3, 4, 5, 6

Any mineral on the hardness scale would scratch minerals below it on the scale. The student tested Mineral 1 and observed that it scratched all other minerals on the hardness scale except orthoclase. When Mineral 2 was tested against fluorite it was observed that neither mineral scratched each other. Which of these is a correct conclusion the student can make about Mineral 1 and Mineral 2?

A: Mineral 2 can be used to scratch apatite and calcite.
B: Mineral 1 can be used to scratch apatite and calcite.
C: Mineral 2 can be used to scratch calcite and orthoclase.
D: Mineral 1 can be used to scratch calcite and orthoclase.

Answer 1

B: Mineral 1 can be used to scratch apatite and calcite.

Step-by-step explanation:

This is because Mineral 1 was able to scratch all other minerals on the hardness scale except orthoclase, which has a higher hardness rating than Mineral 1. This indicates that Mineral 1 has a hardness between 6 (orthoclase) and 5 (apatite), so it should be able to scratch apatite and calcite, which have hardness ratings of 5 and 3 respectively.

On the other hand, Mineral 2 was not able to scratch fluorite, which has a hardness rating of 4. This suggests that Mineral 2 has a hardness rating less than or equal to 4, and therefore cannot scratch apatite or calcite (which have higher hardness ratings of 5 and 3 respectively). Moreover, since Mineral 2 was not scratched by fluorite, it can be concluded that Mineral 2 has a hardness rating equal to or greater than 4, so it could potentially scratch minerals with hardness ratings less than or equal to 4, such as gypsum and talc. However, there is not enough information to conclude that Mineral 2 can scratch calcite or orthoclase.

Answer 2

Based on the observations, the correct conclusion the student can make about Mineral 1 and Mineral 2 is:

D: Mineral 1 can be used to scratch calcite and orthoclase.

Step-by-step explanation:

Mineral 1 was tested against all other minerals on the hardness scale and scratched all of them except orthoclase. This means Mineral 1 has a hardness greater than 6 (harder than orthoclase), making it capable of scratching calcite and orthoclase.

Mineral 2 was tested against fluorite and neither mineral scratched each other. Since fluorite has a hardness of 4, Mineral 2 must have a hardness of 4 or less. Therefore, Mineral 2 cannot scratch apatite (hardness 5) or calcite (hardness 3), as it is softer than both of them.

So, the correct conclusion is that Mineral 1 can be used to scratch calcite and orthoclase, and Mineral 2 cannot scratch apatite and calcite.