The density of the object is 0.25 g/cm3. This is calculated by dividing the mass (20g) by the volume (80cm3).
Mass divided by volume so 120g divided by 80cm3 = 1.5 this particular object would also sink if you put it water bc water has a density of 1.0
Basic mental arithmetic... 2 x 5 x 8 = 80cm3.
80cc is equivalent to 0.08 liters.
When starch is mixed with water, it forms a colloidal suspension where the starch particles disperse in the water but do not dissolve. This mixture can exhibit properties of both a solid and a liquid, such as having a certain viscosity and the ability to retain its shape.