Praseodymium (Pr)

Praseodymium is a chemical element of the periodic table with chemical symbol Pr and atomic number 59 with an atomic weight of 140.908 u and is classed as lanthanide. Praseodymium is solid at room temperature.

Cerium Periodic table Neodymium

Praseodymium in the periodic table

Symbol	Pr
Atomic number	59
Group	-
Period	6
Block	f
Classification	Lanthanide

Appearance	Grayish white
Color	Silver

Number of protons	59 p⁺
Number of neutrons	82 n⁰
Number of electrons	59 e^-

From Wikipedia, the free encyclopediaPraseodymium is a chemical element with symbol Pr and atomic number 59. Praseodymium is a soft, silvery, malleable and ductile metal in the lanthanide group. It is valued for its magnetic, electrical, chemical, and optical properties.

Physical properties

Phase at STP	Solid
Density	6.77 g/cm³
Atomic weight	140.908 u

Thermal properties

Melting point	1208 K 934.85 °C 1714.73 °F
Boiling point	3403 K 3129.85 °C 5665.73 °F
Heat of vaporization	332.63 kJ/mol

Atomic properties

Electronegativity (Pauling Scale)	1.13
Electron affinity	93 kJ/mol
Oxidation states	0, +1, +2, +3, +4, +5 (a mildly basic oxide)
Ionization energies	527 kJ/mol 1020 kJ/mol 2086 kJ/mol 3761 kJ/mol 5551 kJ/mol

Electron configuration for praseodymium

Electron configuration

Shorthand configuration

[Xe] 4f³ 6s²

Electron configuration

Full configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f³ 5s² 5p⁶ 6s²

Electron configuration chart

1s²
2s²	2p⁶
3s²	3p⁶	3d¹⁰
4s²	4p⁶	4d¹⁰	4f³
5s²	5p⁶
6s²

Electrons per shell

2, 8, 18, 21, 8, 2

Valence electrons

2

Valency electrons

4

Bohr model

Figure: Shell diagram of Praseodymium (Pr) atom.

Orbital Diagram

1s

2s

2p

3s

3p

3d

4s

4p

4d

4f

5s

5p

6s

The history of Praseodymium

Discovery

Carl Auer von Welsbach (1885)

Discovery of praseodymium

In 1841, Swedish chemist Carl Gustav Mosander extracted a rare-earth oxide residue he called didymium from a residue he called "lanthana", in turn separated from cerium salts. In 1885, the Austrian chemist Baron Carl Auer von Welsbach separated didymium into two elements that gave salts of different colours, which he named praseodymium and neodymium. The name praseodymium comes from the Ancient Greek πράσινος (prasinos), meaning 'leek-green', and δίδυμος (didymos) 'twin'.

Periodic table history

Identifiers

List of unique identifiers for Praseodymium in various chemical registry databases

CAS Number	7440-10-0
ChemSpider ID	22384
EC number	231-120-3
PubChem CID Number	23942