Answer:
A small amount of solute dissolved in a larger amount of solvent.
Take this analogy to help you understand, if you were to put a teaspoon of sugar in a liter of water it would dissolve, but if you put a sack of sugar in it it would not dissolve! The solute is what is being dissolved and the solvent is what dissolves the solute, so that eliminates some of the options.
Answer:
R.F.M of Iron (II) oxide :

Moles :

Molecules :

Grinding pepper. It is still pepper.
I hope this helps!
The answer would be B) Dunes. I hope you have a wonderful day :)
Answer:
If the molecule is cold enough it will vibrate very slowly but when the molecule warms up it tends to bounce around more
Explanation: