strontium

Traductions

• anglais

  Date : 1983

  Définition

  An element. State: Solid; Group: IIA; Atomic No.: 38; Atomic Wt.: 87.62; Valence: 2; Isotopes: 4 stable. A comparatively soft metal, m.p. 770 °C (1418 °F), of the alkaline-earth group, similar in many respects to calcium. It is quite reactive and quickly forms an oxide coating when exposed to dry air. It has strong reducing properties, decomposing water to evolve hydrogen; it must be protected from moist air by storage under naphtha. In powder form it catches fire spontaneously at room temperature.

  Note :

  It has no important commercial uses, though the bright red color of its flame is utilized in pyrotechnic devices. Two artificial isotopes (89 and 90) formed by nuclear reactions emit highly dangerous ionizing radiation, the 90 isotope having a half life of 28 years; these are so-called bone-seeking isotopes which contaminate plants and thus appear in milk; progress has been made in reducing this hazard by decontamination with vermiculite.

  Termes :

  1. strontium
  2. Sr