(chemistry) Any chemical reaction in which the concentration of some component varies over time or space in a regular periodic manner.

(chemistry) Any chemical reaction initiated by the absorption of a quantum of electromagnetic radiation to form an excited state

(physics) Any nuclear reaction involving a photon and another subatomic particle

(chemistry) Any vessel used to contain the reactants taking part in a reaction.

(chemistry) Any reaction in which a compound is dissociated into its elements, or in which a molecule is dissociated into atoms

(chemistry) A chemical reaction named after its discoverers.

Any engine that generates thrust by expelling matter, especially hot gases produced by igniting a fuel; either a rocket engine or several types of jet engine.

the state resulting from such a reaction / a process involving change in atomic nuclei

(embryology) A reaction that manifests during fertilization, when the sperm cell coalesces with the egg's plasma membrane; this prevents entry of a second sperm

(chemistry, biology) An elimination reaction in which the small molecule removed is water