Fluorite can scratch a copper coin but cannot be scratched by a copper coin.
This is because according to Mohs scale of hardness, fluorite has a hardness of four. Copper has a hardness of three. Therefore fluorite is a harder mineral than copper and will scratch copper but it will not be scratched by copper.
Mohs based his scale on the fact that some minerals could scratch others. If one mineral could scratch another but could not be scratched by it, he reasoned that it must be harder.
Evaporation of water is equal to precipitation of water. I hope this helped :)
The appropriate response is ligament in epiphyseal plate. The epiphysis is the adjusted end of a long bone, at its joint with contiguous bone(s). Between the epiphysis and diaphysis lies the metaphysis, including the epiphyseal plate. It is a hyaline ligament plate in the metaphysis at each finish of a long bone.
Gas is the answer. I hope its the right one but its the best thing i could come up with
