The amount of substance is a basic (or fundamental) quantity that indicates a set of elementary entities and its value is proportional to the number of entities contained in the system. The entities can be atoms, molecules, ions, radicals or other, and must be specified each time to replace the word “substance” (for example the…

The Gilsonite (also known as “uintahite,” “asphaltum” or asphaltite), named by Samuel Gilson, is a natural resinous hydrocarbon derived from petroleum historically discovered in the 1860s in Uintah Basin in northeastern Utah and also present in Colorado, Iran, and Colombia. Gilsonite is soluble in aromatic and aliphatic solvents, as well as in petroleum asphalt. Thanks to its…

There is a chemical bond when an electrostatic force holds together multiple atoms in a chemical species (strong bonds, or primary or intramolecular) or more molecules in a substance in the condensed state (weak, or secondary or intermolecular bonds). The nature of the chemical bond can be explained by observing the coulombic forces interacting between…

Density is the amount of mass per unit volume of a substance or the inverse of specific volume. Density is, therefore, a scalar quantity. The symbol used to represent density in equations is ρ with SI units of kilograms per cubic meter. This term is the reciprocal of specific volume. $\rho=\dfrac{m}{V}\;\left[\dfrac{\textrm{kg}}{\textrm{m}^3}\right]$ For gases, the density…

The plasma is the highest-energy state hot ionized gas consisting of approximately equal numbers of positively charged ions and negatively charged electrons. Like gases, plasmas have no fixed shape or volume and are less dense than solids or liquids. But unlike ordinary gases, plasmas are made up of atoms in which some or all of…

A gas is one of the four fundamental states of matter. In gases, the atoms or molecules are far apart due to they are not bounded at all, meaning, they do not have any attractive forces but only repulsive forces. The interaction of gas particles in the presence of electric and gravitational fields are considered…

Liquid crystals (LCs) are a state of matter which has properties between those of conventional liquids and those of solid crystals. The term liquid crystal is used to indicate the intermediate phases (mesophases) between that of crystalline solid and that of isotropic liquid of some substances. A substance can present several mesophases with a decreasing…

The quantum spin liquid is a state of matter that can be achieved in a system of interacting quantum spins. The word “liquid” refers to a disordered state in comparison to a ferromagnetic spin state (as much in the way liquid water is in a disordered state compared to crystalline ice). However, unlike other disordered…

In liquids, the atoms or molecules are not as tightly bound as in solids, and due to that, they have some freedom to move around. The liquid state is a condensed state of matter, because even in it, as in solids, the particles are linked (weakly) to each other. On the other hand, as liquids…