Atomic NumberAtomic Number of Protactinium
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 YearAbout 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 Symbol | Pa |
| Group | |
| Period | 7 |
| Atomic Weight | 231.03588 u |
| Density | 15.37 g/cm3 |
| Melting Point (K) | 1841 K |
| Melting Point (℃) | 1554 °C |
| Boiling Point (K) | 4300 K |
| Boiling Point (℃) | 4030 °C |
| Heat Capacity | |
| Abundance | 1.4×10−6 mg/kg |
| State at STP | Solid |
| Occurrence | Transient |
| Description | Actinide |
| Electronegativity (Pauling) χ | 1.5 |
| Ionization Energy (eV) | 5.89 |
| Atomic Radius | 180pm |
| Covalent Radius | no datapm |
| Valence Electrons | 2 |
| Year of Discovery | 1917 |
| Discoverer | Soddy, Cranston and Hahn |