Answer:
Save the *minerals* used to extract metals.
You may tell when a solution os formed when the item or particle, such as sugar or salt,
dissolves completely in the solvent, such as water.
Basically, you know when a solution is formed when the material you have placed in the solvent disappears :P
The correct option is B. To get the number of atom for each compound, each element in the compound will be counted as an atom. For instance, for Fe[ClO4]2, there are 1 atom of Fe, 2 atoms of Cl, and 8 atoms of O, making a total of 11 atoms [1 + 2 + 8= 11]. The other options have less than 11 atoms.