When you work with molar mass, you solve for the quantity of ''Moles'' within the substance by converting Mass. The way you can tell the equation is balanced would be by knowing whether the moles were equivalent on both sides or not. Therefore, if they are equal, it is balanced considering you have the same amount of moles on each side of the equation.
Density depends on both the mass and the volume of an object. If you cut a bar of gold in half, you would have two bars with half the mass of the original bar. However, each bar would also have half the volume of the original bar. The density of gold does not change.
The answer is C: The plum-pudding model
