according to mohs hardness scale, your fingernail would be rated as 2.5. juan and carl are trying to…

according to mohs hardness scale, your fingernail would be rated as 2.5. juan and carl are trying to identify an unknown mineral. carl can scratch the mineral sample with his fingernail. juan and carl know the mineral must be one of these four choices. based on the scratch test, the mineral is a apatite b calcite

according to mohs hardness scale, your fingernail would be rated as 2.5. juan and carl are trying to identify an unknown mineral. carl can scratch the mineral sample with his fingernail. juan and carl know the mineral must be one of these four choices. based on the scratch test, the mineral is a apatite b calcite

Answer

Explanation:

Step1: Analyze fingernail hardness

The fingernail has a hardness of 2.5 on Mohs' hardness scale.

Step2: Determine scratch - ability

A mineral can be scratched by a substance with equal or higher hardness. Since the fingernail can scratch the unknown mineral, the unknown mineral has a hardness less than or equal to 2.5.

Step3: Check the options

Apatite has a hardness of 5, which is greater than 2.5. Calcite has a hardness of 3, which is greater than 2.5. Fluorite has a hardness of 4, which is greater than 2.5. Gypsum has a hardness of 2, which is less than 2.5.

Answer:

Gypsum