Density is defined as Mass per unit of Volume. It measures how compact a substance is!
Going by the definition of density, we get the following equation:
D = (Mass) / (Volume)
You know your mass and volume so you can plug in the numbers to get density BUT usually in science courses, we need to find density in terms of SI units. The SI units for density are kg/m^3. You first need to convert your given mass to kg and your given volume to m^3.You can do this using DIMENSIONAL ANALYSIS.
Mass = 43.6 g x [(1 kg) / (1000 g)] = 0.0436kg
(Note: 1000g is 1 kg)
Volume = 25.5 mL x [ (1000 mm^3) / (1 mL)] x [ (1 m^3) / (1000000000 mm^3)] = 2.55 x 10^-5 m^3
(Note: 1000 mm^3 = 1mL and 1 m^3 = (10^-3)^3 mm^3)
Using these values, I can calculate density:
D = (Mass) / (Volume) = 0.0436 kg/(2.55 x 10^-5 m^3) = 1709.803922 = 1.71 x 10^3 kg/m^3