How is friction involved in sledding and skiing?
i just learnt this recently but i need to look through my notes again
answer is: naturally occurring solid, inorganic compound or element is mineral.
minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.
for example magnetite is a mineral of iron oxide (fe₂o₃).
calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).
dolomite is an carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).