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960 terms · page 4 of 40
Average Rate
The overall change in concentration divided by the total time interval over which it occurred.
States of Matter & Gas LawsAvogadro's Law
Equal volumes of all gases at the same temperature and pressure contain equal numbers of molecules.
Foundations of ChemistryAvogadro's Number
The number of elementary entities in one mole of substance, fixed by definition at 6.02214076 × 10²³ mol⁻¹.
Solutions & Colligative PropertiesAzeotrope
A liquid mixture that boils at constant temperature and distils without any change in composition.
Atomic Structure & PeriodicityAzimuthal Quantum Number
The quantum number l that determines the shape of an orbital and the magnitude of the electron's orbital angular momentum.
Chemical Bonding & Molecular StructureBack Bonding
The donation of electron density from a filled orbital on one atom into an empty orbital on its bonded partner, in the direction opposite…
Analytical Chemistry & SpectroscopyBack Titration
A technique in which excess reagent is added and the unreacted portion titrated to find how much reacted with the analyte.
Nuclear & RadiochemistryBackground Radiation
The ionising radiation always present in the environment from natural and artificial sources.
Stoichiometry & Chemical ReactionsBalanced Chemical Equation
An equation in which the number of atoms of each element and the total charge are identical on both sides.
Nuclear & RadiochemistryBand of Stability
The region on a plot of neutron number against proton number within which stable nuclides are found.
Acids, Bases & SaltsBase
A substance that accepts protons, produces hydroxide ions in water, or donates a pair of electrons.
Acids, Bases & SaltsBase Dissociation Constant
The equilibrium constant for the reaction of a base with water to produce hydroxide ions.
Biochemistry & Polymer ChemistryBase Pairing
The specific hydrogen bonding between complementary nitrogenous bases in nucleic acids.
Analytical Chemistry & SpectroscopyBase Peak
The most intense peak in a mass spectrum, assigned an arbitrary relative abundance of 100%.
Acids, Bases & SaltsBasic Buffer
A buffer made from a weak base and one of its salts, giving a pH above 7.
Acids, Bases & SaltsBasic Salt
A salt whose aqueous solution has a pH above 7, or one that retains a hydroxide group.
Acids, Bases & SaltsBasic Solution
A solution in which the hydroxide ion concentration exceeds the hydrogen ion concentration.
Nuclear & RadiochemistryBecquerel
The SI unit of radioactivity, equal to one nuclear disintegration per second.
Analytical Chemistry & SpectroscopyBeer–Lambert Law
The relation stating that absorbance is proportional to concentration and to the path length of the sample.
Chemical Bonding & Molecular StructureBent Geometry
A molecular shape in which two bonded atoms form an angle at a central atom that also carries one or more lone pairs.
Organic ChemistryBenzene
The simplest aromatic hydrocarbon, a planar regular hexagon of six sp² carbons with a delocalised pi cloud.
Nuclear & RadiochemistryBeta-Minus Decay
Radioactive decay in which a neutron converts into a proton, emitting an electron and an antineutrino.
Inorganic & Coordination ChemistryBidentate Ligand
A ligand that binds to the same metal centre through two donor atoms, forming a ring.
Chemical Kinetics & CatalysisBimolecular Reaction
An elementary step in which two species collide and react.