There is water on the pan of the scale as you measure the mass of a mineral. if you were to ignore the water, what would the effect on your density calculation?

The scale measures the mass of a substance and density is mass per unit volume. If the volume is already measured, then ignoring the weight of the water in the pan would decrease the mass being divided by the same amount of volume. This would result in a smaller value for density. For example:
Mass of mineral + water = 10 g
Volume = 10 cubic centimeters
Mass of mineral alone = 8 g
Before removing water, the density would work out to be 
10/10 = 1 g / cm^3
However, if we remove the water,
8/10 = 0.8 g / cm^3

Idont really understand

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.