Question

Density of a substance is defined as
A. Density = Mass x Volume
B. Density = Mass/Volume
C. Density = Volume Mass
D. None

Answer 1

Hint: Density is a physical property of matter that expresses a relationship of mass to volume. If we have two substances of the same volume, then the substance with greater mass will be denser i.e. it will have higher density. For example, 1 litre of mercury is denser than 1 litre of water.

Complete step by step answer:
Have you ever thought about what would happen if we drop a block of balsa wood and a metal nail of the same mass into the water? Will both of them sink or both of them float? Or one will sink and the other will float? Just by using our common sense, we can say that the wooden block will float and the iron nail will sink. However, as they are of the same mass, why does one float and the other sinks? This happens due to the difference in their densities. So, what is density? Say we are looking at two parking lots, one has 10 vehicles in and the other has 4 vehicles. We say that the parking lot with 10 vehicles is denser. Density is simply the measure of how compact the mass in a substance or object is. In scientific terms, density is defined as the ratio of an object's mass to its volume. Density tells us how tightly packed a substance is. Mathematically,
Density = Mass/Volume
Because it is a ratio, the density of material remains the same without regard to how much of that material is present. So, we can say that density is an intensive property of matter. Mass is the amount of matter contained in an object and is commonly measured in units of kilograms (kg). Volume is the amount of space taken up by a quantity of matter and is commonly expressed in cubic meter (${{m}^{3}}$) or in a litre (L) (1 ${{m}^{3}}$ = 1000 L). Therefore, common units used to express density are kilograms per litre (kg/L) and kilograms per cubic metre (kg/${{m}^{3}}$).
Density is the reason because of which some objects sink and other rises. In qualitative terms, it shows how heavy an object is at constant volume.
So, the correct answer to this question is option B.

Note:
It is important to remember, though, that this relationship is not just about how closely packed together with the atoms of an element or the molecules of a compound are. Density is also affected by the atomic mass of an element or compound. Density can vary with temperature and pressure. If we apply pressure to an object its volume decreases, which then increases its density. Increasing the temperature of an object almost always decreases its density by increasing its volume. Since different substances have different densities, density measurements are a useful way of identifying substances.