91Pa
Element 91
Protactinium
Actinides
Protactinium is a chemical element with symbol Pa and atomic number 91.
Key data
- Atomic number
- 91
- Atomic mass
- 231.036 u
- Group / Period
- 3 / 7
- Block
- f-block
- Phase at STP
- Solid
- Density
- 15.37 g/cm³
- Melting point
- 1567.8 °C
- Boiling point
- 4026.8 °C
- Electron configuration
- [Rn] 5f2 6d1 7s2
Common uses
- •Research only
- •Radioactive
- •Decay product of uranium
Discovery
Year: 1913
Discovered by: William Crookes
Named by: Otto Hahn
Frequently asked questions
What is the atomic number of Protactinium?
Protactinium has atomic number 91. Its symbol is Pa and its atomic mass is 231.036 u.
What category of element is Protactinium?
Protactinium is classified as actinides. It sits in group 3, period 7 of the periodic table.
What is Protactinium used for?
Common uses of Protactinium include: Research only, Radioactive, Decay product of uranium.
When was Protactinium discovered?
Protactinium was discovered in 1913 by William Crookes.
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