Final answer:
The Mohs' scale of mineral hardness indicates the unknown mineral in statement H has a hardness greater than calcite (3) and less than apatite (5), while statement J is inaccurate as it suggests the mineral can scratch those harder than 7, which contradicts the scale.
Step-by-step explanation:
The Mohs' scale of mineral hardness is used to classify minerals based on their ability to resist scratching or abrasion. Statement H indicates that the unknown mineral has a hardness level between calcite and apatite, meaning its Mohs hardness would be greater than calcite's (hardness 3) but less than apatite's (hardness 5). On the other hand, statement J is incorrect because if a mineral can scratch apatite, it should only be able to scratch minerals with a hardness of less than or equal to 5, not higher than 7.