Strontium

Symbol: Sr
Atomic number: 38
Category: alkaline earth metals
Group: 2
Period: 5
Block: s
Atomic weight: 87.62 g/mol
Electrons per shell: 2, 8, 18, 8, 2
CAS number: 7440-24-6
Phase: solid
Density: 2.64 kg/l (near room temperature)
Melting point: 1050 K (777C, 1431F)
Boiling point: 1655 K (1382C, 2520F)
Crystal structure: body centered cubic
Oxidation states: 2, 1
Electronegativity: 0.95 (Pauling scale)
Name's origin: Strontian
Name's meaning: is named after the Scottish village, having been discovered in the lead mines there
Facts:
- is a soft silver-white or yellowish metallic element that is highly reactive chemically
- occurs naturally in the minerals celestine and strontianite, but the strontium-90 isotope is present in radioactive fallout and has a half- life of 29
- the primary use for strontium compounds is in glass for colour television cathode ray tubes to prevent X-ray emission
- occurs commonly in nature
- in its pure form strontium is extremely reactive with air and spontaneously combusts