A quadruple bond is a type of chemical bond between two atoms involving eight electrons. This bond is an extension of the more familiar type double bonds and triple bonds. Stable quadruple bonds are most common among the middle members transition metal elements such rhenium, tungsten, molybdenum and chromium.

A quintuple bond in chemistry is an unusual type of chemical bond first reported in 2005 for a dichromium compound. Quadruple bonds are rarer but occur especially for Cr, Mo, W, and Re. In a quintuple bond, ten electrons participate in bonding between the two metal centers.

A peptide bond (amide bond) is a covalent chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, causing the release of a molecule of water. Hence the process is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids.

A dipolar bond, also known as dative covalent bond or coordinate bond is a kind of 2-centre, 2-electron covalent bond in which the two electrons derive from the same atom. Typically, a dipolar bond is formed when a Lewis base donates a pair of electrons to a Lewis acid.

Hyperconjugation is the interaction of the electrons in a sigma bond (usually C-H or C-C) with an adjacent empty (or partially filled) non-bonding p-orbital or antibonding π orbital or filled π orbital, to give an extended molecular orbital that increases the stability of the system. Only electrons in bonds that are β to the positively charged carbon can stabilize a carbocation by hyperconjugation.

A fictitious force, also called a pseudo force is an apparent force that acts on all masses in a non-inertial frame of reference, such as a rotating reference frame. The force F does not arise from any physical interaction but rather from the acceleration a of the non-inertial reference frame itself.

The term hapticity is used to describe how a group of contiguous atoms of a ligand are coordinated to a central atom. Hapticity of a ligand is indicated by the Greek character 'eta', η.

A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two identical atoms. The strength of the bond to each of those atoms is equal. It is an example of a 3-center 4-electron bond.

Immunohistochemistry or IHC refers to the process of detecting antigens (e.g., proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots immuno, in reference to antibodies used in the procedure, and histo, meaning tissue (compare to immunocytochemistry).

Liquid foams can be used in fire retardant foam, found use in extinguishing fires, especially oil fires. In some ways, leavened bread is a foam, as the yeast causes the bread to rise by producing tiny bubbles of gas in the dough.

A foam is a substance that is formed by trapping many gaseous bubbles in a liquid or solid. A foam is normally an extremely complex system consisting of polydisperse gas bubbles separated by draining films.

Femtochemistry is the science that studies chemical reactions on extremely short timescales, approximately 10^-15 seconds (one femtosecond, hence the name).

Nanofoams are a class of nanostructured, porous materials, foams, containing a significant population of pores with diameters less than 100 nm. Aerogel is an example of nanofoam.

Aerogel is a manufactured material with the lowest bulk density of any known porous solid. It is derived from a gel in which the liquid component of the gel has been replaced with a gas. The result is an extremely low-density solid, with a notable effectiveness as a thermal insulator.

Amphiphile is a term describing a chemical compound possessing both hydrophilic (water-loving, polar) and lipophilic (fat-loving) properties. Such a compound is called amphiphilic or amphipathic.

In chemistry, an ideal solution or ideal mixture is a solution with thermodynamic properties analogous to those of a mixture of ideal gases. The enthalpy of solution (or enthalpy of mixing) is zero as is the volume change on mixing; the closer to zero the enthalpy of solution is, the more ideal the behavior of the solution becomes.

The term number concentration is used in chemistry for the intensive quantity, particularly when comparing with other concentrations.

Dilution is a reduction in the concentration of a chemical (gas, vapor and solution). It is the process of reducing the concentration of a solute in solution, usually simply by mixing with more solvent. To dilute a solution means to add more solvent without the addition of more solute.

In chemistry, a mixture is a material system made up by two or more different substances which are mixed together but aren't combined chemically. Mixture refers to the physical combination of two or more substances the identities of which are retained. It can be either homogeneous or heterogeneous.

Particle aggregation in materials science is direct mutual attraction between particles (atoms or molecules) via van der Waals forces or chemical bonding. When there are collisions between particles in fluid, there are chances that particles will attach to each other and become larger particle. There are 3 major physical mechanisms to form aggregate: Brownian motion, fluid shear and differential settling.

Helium is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table.Helium is used in cryogenics (its largest single use, absorbing about a quarter of production), particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners.

Xenon tetrafluoride is a chemical compound with chemical formula XeF₄. It was the first discovered binary compound of a noble gas. It is produced by the chemical reaction of xenon with fluorine.

This is not an air gas. This gas is a synthesis gas usually produced from the reaction of calcium carbide with water. Acetylene is a gaseous hydrocarbon. It has a strong garlic odor. The gas is colorless, unstable, highly combustible. Acetylene is used in machine/metal construction for cutting and welding (with oxygen). It is also used in the glass industry for lubrication of bottle production molds.

Cryogenic gas is a gas which has been supercooled such that it is a liquid or solid at a standard temperature.Cryogenic gases are liquefied gases at standard temperature and pressure. They are kept in their liquid state at very low temperatures. Cryogenic gases are very popular and they are used as fuels, oxidizers and refrigerants. These gases are to be stored properly to get their maximum usage.

Nerve gases, such as Tabun (or GA), Sarin (or GB), and Soman (or GD), are colorless, odorless, and tasteless. These gases destroy the normal functioning of nerves and muscles. It can be easily absorbed through the skin by means of inhalation or ingestion. The victim dies within a few minutes after the poisons enter the blood.