Strontium

estroncio

Strontium was discovered in 1791, in an ore found near the Scottish town of Strontia. The ore burned with a bright crimson flame, and the Scottish chemist Thomas Charles Hope studied it and discovered that it contained a new element. This mineral is called strontianite, and it is the main strontium mineral. Thus, in 1808, the chemist Humphry Davy extracted the element from the mineral for the first time, by means of an experiment using electricity. In the past, it was used in television screens, but is less commonly used today. Strontium oxide is used in ceramics and ceramic glazes to create distinctive colors, while strontium carbonate imparts a red color to sparklers and fireworks. Magnets containing iron oxide can be strengthened by the addition of strontium. These powerful magnets are used in loudspeakers and microwave ovens. Strontium chloride is added to some types of toothpaste. On the other hand, radioactive strontium is used as a source of electricity for radar stations in remote locations where there are no power lines or fuel supplies.

Summary of properties (Sr)

Atomic weight87.62(1)
Discoverer (year)Crawford, Adair (1790)
Natural formmetallic solid (face centered cubic)
Electron configuration[Kr] 5s2
Melting point (ºC)769
Boiling point (ºC)1384
Abundance in earth's crust (ppm)370
Isotope (abundance)84Sr (0.56), 86Sr (9.86), 87Sr (7.00), 88Sr (82.58)
Density g/cm32.54
Van der Waals radius (pm)249
Covalent radius (pm)190
Electronegativity (Pauling)0.95
Vaporization enthalpy (kJ/mol)139.00
Enthalpy of fusion (kJ/mol)7.43
Specific heat capacity (J/g·K) at 25ºC and 1 atm0.30
Thermal conductivity (W/cm·K) at 25ºC and 1 atm0.350
Oxidation state+2
Electron affinity (eV)0.05
1st Ionization potential (eV)5.6949

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