Thorium

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General Properties
Atomic number Predicted atomic mass Half-life of longest living isotope Electron Configuration Density Melting point Boiling point First discovered Occurance
91 231.036amu Around 32,500 years [Rn] 5f2 6d1 7s2 15.4g/cm3 1572°C 4000°C 1913 Various uranium ores
General Properties
Atomic number 91
Atomic mass 231.036amu
Half-life of longest living isotope Around 32,500 years
Electron Configuration [Rn] 5f2 6d1 7s2
Density 15.4g/cm3
Melting point 1572°C
Boiling point 4000°C
First discovered 1913
Occurance Various uranium ores

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Description and uses

Protactinium is the 91st element of the periodic table, and one of the elements predicted by Mendeleev. It was discovered in 1913 by Kasimir Fajans and Otto Göhring, when they extracted it from uranium. Its longest living isotope is 231Pa, with a half life of 32,500 years.

T&C