Final answer:
The Mohs scale is used to determine the hardness of an unknown mineral by scratching it against reference minerals. If the unknown mineral can scratch another, it is harder, but if it cannot, it is softer, include all three options final answer.
Step-by-step explanation:
To determine the hardness of an unknown mineral, we can use the concepts described by Mohs' scale of mineral hardness. This scale is a qualitative scale developed in 1822 by Frederich Mohs, which ranks the hardness of minerals in relation to ten reference minerals. When a mineral can scratch another mineral, it is considered to be harder. In the context of the student's question, we can assume the following:
- The unknown mineral is harder than the minerals that it was able to scratch. The ability to scratch a specific mineral indicates that the unknown mineral has a higher placement on the Mohs scale in comparison to those it scratched.
- The unknown mineral is not harder than the mineral that it was not able to scratch. If the unknown mineral fails to scratch a reference mineral, it suggests that the unknown mineral has a lower hardness value on the Mohs scale.
- The unknown mineral is a relatively hard mineral, especially if it is able to scratch materials known to have a higher hardness value, such as glass.
To conclude, based on the given information and Mohs' scale, the correct option for the student's answer would be: 1) The unknown mineral is harder than the minerals that it was able to scratch, 2) The unknown mineral is not harder than the mineral that it was not able to scratch, 3) The unknown mineral is a relatively hard mineral.