A sample has a mass of 1.2 g and a volume of 1.1 cm? What is the density of this sample?

Density is a physical quantity, defined as the ratio of body mass to the volume occupied by this body.  The average body density is the ratio of body weight to its volume.

Since the mass in a body can be distributed unevenly, a more adequate model defines the density at each point of the body as a derivative of mass over volume.

Thus, to obtain the density of a sample, its mass must be divided by its volume. Thus, the density of the sample is 1.2 / 1.1, that is, 1.09 g/cm3.

c is the answer because when something is left after something evaporates that shows the chemical change.