Physical Chemistry Test

Thermospray is a form of atmospheric pressure ionization in mass spectrometry. It transfers ions from the liquid phase to the gaseous phase for analysis. It is particularly useful in liquid chromatography-mass spectrometry.

Heavy ion refers to an ionized atom which is usually heavier than helium. Heavy-ion physics is devoted to the study of extremely hot nuclear matter and the collective effects appearing in such systems, differing from particle physics, which studies the interactions between elementary particles.

In chemistry, bond energy (E) is a measure of bond strength in a chemical bond. It is the heat required to break one Mole (unit) of molecules into their individual atomsb

In chemistry, a dihydrogen bond is a kind of hydrogen bond, an interaction between a metal hydride bond and an OH or NH group or another proton donor.

A glycosidic bond is formed between the hemiacetal group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some organic compound such as an alcohol.It is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate.

The term hapticity is used to describe how a group of contiguous atoms of a ligand are coordinated to a central atom.

Conjugation is the overlap of one p-orbital with another across an intervening sigma bond (in larger atoms d-orbitals can be involved). A conjugated system has a region of overlapping p-orbitals, bridging the interjacent single bonds. They allow a delocalization of pi electrons across all the adjacent aligned p-orbitals.

Salt bond falls into the broader category of noncovalent interactions. A salt bond is actually a combination of two noncovalent interactions: hydrogen bonding and electrostatic interactions .This is most commonly observed to contribute stability to the entropically unfavourable folded conformation of proteins.

The 3-centre-4-electron bond is a model used to explain bonding in hypervalent molecules such as phosphorus pentafluoride, sulfur hexafluoride, the xenon fluorides, and the bifluoride ion.

Electrovalency is a measurement of the net electric charge of an ion and is used when balancing chemical reactions. Electrovalency is related to the concepts of electronegativity and valence electrons, and indicates the number of electrons necessary for an ion to have a balanced electric charge.

A catch bond is a type of noncovalent bond whose dissociation lifetime increases with tensile force applied to the bond. Normally, bond lifetimes are expected to diminish with force.

Denticity refers to the number of atoms in a single ligand that bind to a central atom in a coordination complex.

A sextuple bond is a type of covalent bond involving 12 bonding electrons and in which the bond order is 6. The only known molecules with true sextuple bonds are the diatomic dimolybdenum (Mo2) and ditungsten (W2), which exist in the gaseous phase.

Atomic spectroscopy is the determination of elemental composition by its electromagnetic or mass spectrum. Atomic spectroscopy is closely related to other forms of spectroscopy.

A network covalent solid consists of atoms held together by a network of covalent bonds and hence can be regarded as a single, large molecule. The classic example is diamond; other examples include silicon, quartz, and graphite.

An exergonic reaction is a chemical reaction where the change in the Gibbs free energy is negative, indicating a spontaneous reaction.

Intercalation is the reversible inclusion of a molecule (or group) between two other molecules (or groups). Examples include DNA intercalation and graphite intercalation compounds.

The standard enthalpy of reaction is the enthalpy change that occurs in a system when one mole of matter is transformed by a chemical reaction under standard conditions.

A non-covalent bond is a type of chemical bond, typically between macromolecules, that does not involve the sharing of pairs of electrons, but rather involves more dispersed variations of electromagnetic interactions.

Spark ionization is a method used to produce gas phase ions from a solid sample. The prepared solid sample is vapourized and partially ionized by an intermittent discharge or spark.

An ion source is an electro-magnetic device that is used to create charged particles. These are used primarily to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.

London dispersion force is a weak intermolecular force arising from the quantum induced instantaneous polarization multipoles in molecules. They can act between molecules without permanent multipole moments.These are exhibited by nonpolar molecules because of the correlated movements of the electrons in interacting molecules.

The mesomeric effect or resonance effect in chemistry is a property of substituents or functional groups in a chemical compound. The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is symbolized by the letter M.