Mixtures B, C, and D can be separated by distillation. Pebbles and sand can't.
If some salt is dissolved in a beaker of water, then the salt is the solute and the water is the solvent.
The equation is not balanced because the number of atoms of each element on the left is not equal to the number of atoms of that element on the right. In fact, the total number of all atoms on the left (8) is not even equal to the total number of all atoms on the right (10).
