Density (Meaning and Explanation)

We explain what density is and some characteristics of this property. In addition, other types of density exist.

What is density?

The term “density” comes from the field of physics and chemistry and refers to the relationship that exists between the mass of a substance (or a body) and its volume. This is an intrinsic property of matter, since it does not depend on the amount of substance considered.

Density, a property that usually It is expressed in kilogram per cubic meter (kg/m³) or gram per cubic centimeter (g/cm³) varies to a greater or lesser extent depending on pressure and temperature, and also with changes of state.

Due to the little cohesion between their particles, gases generally have a lower density than liquids and liquids have a lower density than solids.

The density of matter It is often associated with the story of the Greek philosopher Archimedes who was tasked with determining whether their king's crown had been forged using pure gold or whether it had been made from an alloy with other metals.

During an immersion bath, Archimedes realized that he could calculate the volume of the crown by submerging it in water and measuring the displacement of the liquid, without having to melt or break it, and that by knowing the density of gold (which is a constant) he could then weigh the crown and determine (using the formula) whether it was pure gold or an alloy (the density of the gold would have varied when mixed with other metals).

Other types of density

Density - osteoporosis — Low bone mineral density can trigger osteoporosis.

Population density. It is a demographic concept that refers to the number of inhabitants per square kilometer. China and India are examples of countries with very high population density, while the Nordic countries and Oceania have low population density. Areas of high population density are often associated with housing problems, air pollution, insufficient public service infrastructure, among others.
Optical density. It is a physical parameter that constitutes the absorption of an optical element at a given wavelength per unit distance. This data is used to assess the cell content, quality of smoke generated by different substances, laser power, filters, etc.
Electric current density It is the relationship that exists between the intensity of electric current that flows through a conductor per unit of time and per unit of cross section.
Magnetic flux density Also called “magnetic induction,” it is the magnetic flow that causes an electric charge to move for each unit area normal to the direction of the flow.
Bone mineral density In the field of medicine, this measurement refers to the amount of minerals per unit area. It is usually expressed in g/cm² and is established for certain bones specifically, such as the femur or the lumbar spine. A low bone mineral density can trigger osteoporosis, a disease in which the bones have a very low proportion of minerals (mainly calcium), making them too porous and, therefore, fragile and brittle, thus increasing the risk. of people to suffer fractures.