<span>An unsaturated solution is one that has a concentration lower than it's solubility. What happens is all of the solute dissolves in the solvent. For example, dumping a spoon of sugar into coffee ends up with an unsaturated solution. Because all the sugar dissolves into the solvent (the coffee).</span>
Adding and subtracting with scientific notation may require more care, because the rule for adding and subtracting exponential expressions is that the expressions must havelike terms<span>. Remember that to be </span>like terms<span>, two expressions must have exactly the same base numbers to exactly the same powers. Thinking about decimal arithmetic, the requirement that we have the same powers makes sense, because that guarantees that all of the place values are lined up properly.</span>
The answer to this question is A
C. The mass number is the amount of Protons and electrons there are combined, so 200 - 80 is 120.
