Strontium Strontium Strontium is the chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these. While natural strontium is stable, the synthetic Sr isotope is radioactive and is one of the most dangerous components of
Metallic dragon and adamantine dragons for brass and bronze, and released the latter dragons in a later book alongside cobalt, mercury, mithral, orium, and steel dragons. The classification of "metallic dragons" was used in the "Advanced Dungeons & Dragons" second edition "Monstrous Manual" (1993), although the gold(en) dragon first appeared in the original "Dungeons & Dragons" "white box" set (1974) and the other dragons comprising the category had been in print since the first edition "Monster Manual" (1977). The term was continued in use in the third edition and fourth edition "Monster Manual". Although weaker than many other varieties of dragonkind, brass