Rock cycle - a process in which a rock forms, changes from one type of rock to another, forms again by processes on and in the Earth.
Metamorphic Rock - Rocks changed by intense heat or extreme pressure.
Sedimentary Rock - A rock that forms when sediments are compacted and cemented together.
Igneous Rock - A rock that forms when molten rock cools and hardens.
You have not mention here about those elements but the general concept for this is the:
uneven distribution ------> polar
even distribution -------> non-polar
A. proton donating is often referring to Hydrogen donating in acids. See the extra H+ in common acids: HCl, H2SO4
1 liter= 1,000,000 microliters
20 mL= 20,000 microliter
I hope this helped ;)))