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Stoichiometry & Chemical Reactions

Product

A substance formed as a result of a chemical reaction.

mol
Chemical Kinetics & Catalysis

Promoter

A substance that has little catalytic activity itself but greatly increases the effectiveness of a catalyst.

Dimensionless
Biochemistry & Polymer Chemistry

Protein

A large biomolecule made of one or more chains of amino acids folded into a specific three-dimensional shape.

g/mol
Atomic Structure & Periodicity

Proton

A positively charged subatomic particle found in the atomic nucleus, carrying a charge of +1 elementary unit.

m_p = 1.6726 × 10⁻²⁷ kg u
Acids, Bases & Salts

Proton Affinity

The energy released when a gaseous species accepts a proton, measuring intrinsic basicity free of solvent effects.

B(g) + H⁺(g) → BH⁺(g) kJ/mol
Chemical Kinetics & Catalysis

Pseudo-First-Order Reaction

A higher-order reaction that behaves as first order because one reactant is present in such large excess that its concentration is…

rate = k′[A], k′ = k[B]₀ s⁻¹
Foundations of Chemistry

Pure Substance

Matter with a fixed chemical composition and a definite set of physical properties, comprising either a single element or a single compound.

Dimensionless
Foundations of Chemistry

Purity

The mass fraction of the desired substance in a sample, usually expressed as a percentage of the total mass.

purity % = (mass of pure substance / total mass) × 100 Dimensionless
Stoichiometry & Chemical Reactions

Pyrolysis

The thermal decomposition of a substance at high temperature in the absence of oxygen.

complex → simpler fragments (Δ, no O₂) °C
Analytical Chemistry & Spectroscopy

Qualitative Analysis

Analysis carried out to establish which species are present in a sample.

Dimensionless
Analytical Chemistry & Spectroscopy

Quantitative Analysis

Analysis carried out to determine the amount or concentration of a species in a sample.

Various
Atomic Structure & Periodicity

Quantum Mechanical Model

The modern description of the atom in which electrons are represented by wavefunctions giving probability distributions rather than…

Ĥψ = Eψ Dimensionless
Biochemistry & Polymer Chemistry

Quaternary Structure

The arrangement of two or more folded polypeptide chains into a functional protein complex.

Dimensionless
Organic Chemistry

Racemic Mixture

An equimolar mixture of two enantiomers, which shows no net optical rotation.

50:50 (+) and (−) degrees
Nuclear & Radiochemistry

Radiation Dose

A measure of the energy deposited in matter by ionising radiation.

D = E / m Gy
Nuclear & Radiochemistry

Radioactive Activity

The number of nuclear disintegrations occurring in a sample per unit time.

A = λN Bq
Nuclear & Radiochemistry

Radioactive Decay Series

A sequence of successive radioactive decays leading from a long-lived parent to a stable end product.

Dimensionless
Nuclear & Radiochemistry

Radioactive Half-Life

The time required for half the nuclei in a radioactive sample to decay.

t½ = 0.693 / λ s
Nuclear & Radiochemistry

Radioactive Tracer

A radioisotope introduced into a system so that its pathway can be followed by detecting its radiation.

Bq
Nuclear & Radiochemistry

Radioactive Waste

Material containing radionuclides for which no further use is foreseen and which requires controlled disposal.

Bq/kg
Nuclear & Radiochemistry

Radioactivity

The spontaneous emission of particles or electromagnetic radiation from unstable atomic nuclei.

Bq
Nuclear & Radiochemistry

Radiocarbon Dating

A dating technique that determines the age of organic material from its residual carbon-14 content.

t = (t½ / 0.693) ln(N₀/N) years
Nuclear & Radiochemistry

Radioisotope

An isotope of an element whose nucleus is unstable and undergoes radioactive decay.

Dimensionless
Nuclear & Radiochemistry

Radiolysis

The chemical decomposition of a substance caused by ionising radiation.

H₂O →(radiation) H· + OH· Dimensionless