Strontium

38
Sr
Gruppe
2
Periode
5
Blok
s
Protons
Electrons
Neutrons
38
38
50
General Properties
Atomnummer
38
Atommasse
87,62
Mass Number
88
Kategori
Jordalkalimetaller
Farve
Silver
Radioactive
Nej
Named after Strontian, a town in Scotland
Krystalstruktur
Fladecentreret Kubisk
History
Strontium was recognized as a new element in 1790 when Adair Crawford and his colleague William Cruickshank analyzed a mineral sample from a lead mine near Strontian, Scotland.

The element was eventually isolated by Sir Humphry Davy in 1808.

The isolation was done by the electrolysis of a mixture containing strontium chloride and mercuric oxide.
Elektroner i hver skal
2, 8, 18, 8, 2
Elektronkonfiguration
[Kr] 5s2
Sr
Strontium metal turns yellow when exposed to air
Physical Properties
Tilstandsform
Fast stof
Massefylde
2,64 g/cm3
Smeltepunkt
1050,15 K | 777 °C | 1430,6 °F
Kogepunkt
1655,15 K | 1382 °C | 2519,6 °F
Smeltevarme
8 kJ/mol
Fordampningsvarme
137 kJ/mol
Varmefylde
0,301 J/g·K
Abundance in Earth's crust
0,036%
Abundance in Universe
4×10-6%
The
Billede akkrediteringer: Wikimedia Commons (Alchemist-hp)
The chemical element strontium as a synthetic made crystals, sealed under argon in a glas ampoule
CAS Number
7440-24-6
PubChem CID Number
5359327
Atomic Properties
Atomradius
215 pm
Kovalent radius
195 pm
Elektronegativitet
0,95 (Paulings skala)
Ionization Potential
5,6949 eV
Atomic Volume
33,7 cm3/mol
Varmeledningsevne
0,353 W/cm·K
Oxidationstrin
1, 2
Applications
The primary use for strontium is in glass for color television cathode ray tubes.

Strontium salts are used in flares and fireworks for a crimson color.

Strontium chloride is used in toothpaste for sensitive teeth.

Strontium oxide is used to improve the quality of pottery glazes.
Strontium's non-radioactive isotopes are considered non-toxic
Isotoper
Stable Isotopes
84Sr, 86Sr, 87Sr, 88Sr
Unstable Isotopes
73Sr, 74Sr, 75Sr, 76Sr, 77Sr, 78Sr, 79Sr, 80Sr, 81Sr, 82Sr, 83Sr, 85Sr, 89Sr, 90Sr, 91Sr, 92Sr, 93Sr, 94Sr, 95Sr, 96Sr, 97Sr, 98Sr, 99Sr, 100Sr, 101Sr, 102Sr, 103Sr, 104Sr, 105Sr