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Protactinium , including Technical Data, Safety Data and its high purity propertiesresearch, applications and other useful facts are discussed below. Scientific facts such as the atomic structure,ionization energyabundance on Earthconductivity and thermal properties are included. 

Protactinium is a Block F, Group 3, Period 7 element. The number of electrons in each of Protactinium‘s shells is 2, 8, 18, 32, 20, 9, 2 and its electronic configuration is [Rn] 5f2 6d1 7s2. In its elemental form protactinium‘s CAS number is 7440-13-3 The protactinium atom has a radius of and it‘s Van der Waals radius is Protactinium is toxic and radioactive. 

Protactinium is found in the form of two isotopes: protactinium-231 and protactinium-234. Protactinium was discovered by Otto Hahn and Lise Meitner  in 1917. The name Protactinium originates from the Greek word ‘Porots‘ which means first. 

Protactinium Abundance. The following table shows the abundance of protactinium and each of its naturally occurring isotopes on Earth along with the atomic mass for each isotope.
Isotope Atomic Mass % Abundance on Earth
Pa-231 231.035879 -

Protactinium Safety Data. The safety data for protactinium metalnanoparticles and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the left margin. Protactinium compounds have no biological role. 

Ionization Energy. The ionization energy for protactinium (the least required energy to release a single electron from the atom in it‘s ground state in the gas phase) is stated in the following table:
1st Ionization Energy 568.30 kJ mol-1
2nd Ionization Energy - kJ mol-1
3rd Ionization Energy - kJ mol-1

Conductivity. As to protactinium‘s electrical and thermal conductivity, the electrical conductivity measured in terms of electrical resistivity @ 20 ?C is 19.1   ?Ocm and its electronegativities (or its ability to draw electrons relative to other elements) is 1.5. The thermal conductivity of protactinium is 4.7 W m-1K-1. 

Thermal Properties of Protactinium. The melting point and boiling point for protactinium are statedbelow. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
Heat of Fusion 16.7 kJ mol-1
Heat of Vaporization 481 kJ mol-1
Heat of Atomization 607 kJ mol-1

Formula Atomic Number Molecular Weight Electronegativity (Pauling) Density Melting Point Boiling Point Vanderwaals radius Ionic radius Energy of first ionization
Pa 91 231 g.mol -1 1.5 15.37 g/L -111.7? °C 1568 °C .200 nm - pm 568.30 kJ.mol-1