Strontium

Images

Image

Attribution: Alchemist-hp

Animated Strontium

History

Named after Strontian, a town in Scotland. Isolated by Davey by electrolysis in 1808, however, Adair Crawford recognized a new mineral (strontianite) as differing from other barium minerals in 1790.

Uses

In addition to the medical imaging application described in the image caption above, strontium has found use in producing ferrite magnets and in refining zinc. Strontium titanate is an interesting optical material as it has an extremely high refractive index and an optical dispersion greater than that of diamond. It has been used as a gemstone, but is very soft. It does not occur naturally.

Forms

Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropic forms of the metal exist, with transition points at 235 and 540°C.

Isotopes

Sixteen other unstable isotopes are known to exist. Of greatest importance is 90Sr with a half-life of 29 years. It is a product of nuclear fallout and presents a health problem. This isotope is one of the best long-lived high-energy beta emitters known, and is used in SNAP (Systems for Nuclear Auxilliary Power) devices. These devices hold promise for use in space vehicles, remote weather stations, navigational buoys, etc., and where a lightweight, long-lived, nuclear-electric power source is needed.

General Info

AtomicNumber
38
Symbol
Sr
Name
Strontium

Atomic Info

Appearance
AtomicWeight
87.62(1)
Color
00FF00
ElectronicConfiguration
[Kr] 5s2
ElectronegativityInPauling
0.95
AtomicRadiusInPM
192
IonRadiusInPM
118 (+2)
VanDerWaalsRadiusInPM
IEinKJmol
550
EAinKJmol
-5
OxidationStates
2
StandardState
solid
BondingType
metallic
MeltingPoint
1050
BoilingPoint
1655
Density
2.63
State
Alkaline earth metal
DiscoveredYear
1790