Name: strontium
Symbol: Sr
Atomic number: 38
Atomic weight: 87.62 (1) g r
Group in periodic table: 2
Group name: Alkaline earth metal
Period in periodic table: 5
Block in periodic table: s-block
CAS registry ID: 7440-24-6
Strontium does not occur as the free element. Strontium is softer than calcium and decomposes water more vigorously. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish colour with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart an excellent crimson colour to flames, and these salts are used in pyrotechnics.