Atomic Number of Protactinium

Protactinium Atomic Number

Atomic Number of Protactinium is 91.

Chemical symbol for Protactinium is Pa. Number of protons in Protactinium is 91. Atomic weight of Protactinium is 231.03588 u or g/mol. Melting point of Protactinium is 1554 °C and its the boiling point is 4030 °C.

» Boiling Point » Melting Point » Abundant » State at STP » Discovery Year

About Protactinium

Protactinium is a radioactive metal of shiny light grey color. It was discovered in the beginning of the last century and given the name after the Greek expression meaning the first active. It is hardly possible to obtain this element in its natural form as only very small amounts of it exist in natural ores. It can be extracted in nuclear reactors. Protactinium has no biological importance and is only used for the purposes of scientific research.

Properties of Protactinium Element

Atomic Number (Z)91
Atomic SymbolPa
Atomic Weight231.03588 u
Density15.37 g/cm3
Melting Point (K)1841 K
Melting Point (℃)1554 °C
Boiling Point (K)4300 K
Boiling Point (℃)4030 °C
Heat Capacity
Abundance1.4×10−6 mg/kg
State at STPSolid
Electronegativity (Pauling) χ1.5
Ionization Energy (eV)5.89
Atomic Radius180pm
Covalent Radiusno datapm
Valence Electrons2
Year of Discovery1917
DiscovererSoddy, Cranston and Hahn

What is the Boiling Point of Protactinium?

Protactinium boiling point is 4030 °C. Boiling point of Protactinium in Kelvin is 4300 K.

What is the Melting Point of Protactinium?

Protactinium melting point is 1554 °C. Melting point of Protactinium in Kelvin is 1841 K.

How Abundant is Protactinium?

Abundant value of Protactinium is 1.4×10−6 mg/kg.

What is the State of Protactinium at Standard Temperature and Pressure (STP)?

State of Protactinium is Solid at standard temperature and pressure at 0℃ and one atmosphere pressure.

When was Protactinium Discovered?

Protactinium was discovered in 1917.