Periodic table

 

 

Atomic number:91

Group numbers:3

Period:7

Electronic configuration:[Rn] 5f² 6d¹ 7s²

Formal oxidation number:+4 +5

Electronegativities:1.5

Atomic radius / pm:156.1

Relative atomic mass:231.03588 ± 0.00002

 

Protactinium was discovered by Kasimir Fajans and Otto H. Göhring (DE) in 1913. The origin of the name comes from the Greek word protos meaning first. It is a very rare, silvery-white, extremely radioactive metal that resists alkalis, reacts with oxygen, acids and steam. Protactinium is highly radiotoxic, extremely toxic and must be handled with great care. Protactinium does not occur in nature. It is found among fission products of uranium, thorium and plutonium.

PHYSICAL PROPERTIES

Density / g dm^-3:15370 (calc.)

Molar volume / cm³mol^-1:15.03 (calc.)

Electrical resistivity / μΩcm:19.1 (20 °C)

THERMAL PROPERTIES

Thermal conductivity / W m^-1K^-1:47

Melting point / °C:1572

Boiling point / °C:-

Heat of fusion / kJ mol^-1:16.7

Heat of vaporization / kJ mol^-1:481

Heat of atomization / kJ mol^-1:607

IONIZATION ENERGIES

First ionization energy / kJ mol^-1:568.30

Second ionization energy / kJ mol^-1:-

Third ionization energy / kJ mol^-1:-

ABUNDANCE OF ELEMENTS

in the atmosphere / ppm:-

in the Earth's crust / ppm:2E-12

in the oceans / ppm:-

CRYSTALLOGRAPHIC DATA

ISOTOPES

REDUCTION POTENTIALS

 

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Citing this page:

Generalic, Eni. "Protactinium." EniG. Periodic Table of the Elements. 16 May 2013. KTF-Split. {Date of access}. <http://www.periodni.com/pa.html>.