strontium

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A soft, silvery, easily oxidized metallic element that ignites spontaneously in air when finely divided. Strontium is used in pyrotechnic compounds and various alloys. Atomic number 38; atomic weight 87.62; melting point 769°C; boiling point 1,384°C; specific gravity 2.54; valence 2. See Table at element.

Century Dictionary and Cyclopedia

1. n. Chemical symbol, Sr; atomic weight, 87.37; specific gravity, 2.54. A dark-yellow metal, less lustrous than barium, malleable, and fusible at a red heat. When heated in air, it burns with a bright flame to the oxid. It decomposes water at ordinary temperatures, evolving hydrogen, and uniting with the oxygen of the water to form the oxid strontia. It does not occur native. The chief strontium minerals are the carbonate (strontianite) and the sulphate (celestine). Strontium also occurs as a silicate in the mineral brewsterite. It has been detected in the waters of various mineral springs, as well as in sea-water, and in the ashes of some marine plants. Salts of strontium are chiefly used in pyrotechny, imparting an intense red color to flames.

Wiktionary

1. n. A metallic chemical element (symbol Sr) with an atomic number of 38.

GNU Webster's 1913

1. n. (Chem.) A metallic element of the calcium group, always naturally occurring combined, as in the minerals strontianite, celestite, etc. It is isolated as a yellowish metal, somewhat malleable but harder than calcium. It is chiefly employed (as in the nitrate) to color pyrotechnic flames red. Symbol Sr. Atomic weight 87.3.

WordNet 3.0

1. n. a soft silver-white or yellowish metallic element of the alkali metal group; turns yellow in air; occurs in celestite and strontianite