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.
Explanation:
Overgrazing is the major cause of desertification worldwide. Other factors that cause desertification include urbanization, climate change, overdrafting of groundwater, deforestation, natural disasters and tillage practices in agriculture that place soils more vulnerable to wind.
Declining krill populations will have catastrophic consequences for ecosystem homeostasis and it will increase the levels of phytoplankton.
<h3>What is ecosystem homeostasis?</h3>
The term ecosystem homeostasis makes reference to the state of equilibrium between different species in an ecosystem.
Krill are fundamental primary consumers in aquatic environments and they eat autotrophic phytoplankton.
In conclusion, declining krill populations will have catastrophic consequences for ecosystem homeostasis and it will increase the levels of phytoplankton.
Learn more about ecosystem homeostasis here:
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