The chemical element (symbol Rn, formerly Ro) with atomic number 86. It is an odorless, colorless, chemically inert but radioactive noble gas. / The most stable isotope of this element, ²²²₈₆Rn.

plural of radonate

(inorganic chemistry) Any oxyanion of radon; any salt containing such an anion

(geometry) A theorem on convex sets, stating that any set of d + 2 points in Rᵈ can be partitioned into two sets whose convex hulls intersect.

(mathematics) A measure on the σ-algebra of Borel sets of a Hausdorff space that is locally finite and inner regular.

plural of Radon measure

(dated) The unstable, radioactive, chemical element with atomic number 118, now named oganesson.

A small glass or gold tube, containing radon gas, implanted in a patient as radiotherapy.

plural of radon seed

(geometry) A point in the intersection of convex hulls specified by Radon's theorem.