Promethium

Promethium,  ₆₁Pm

General properties
Name, symbol	Promethium, Pm
Pronunciation	/proʊˈmiːθiəm/ (proh-MEE-thee-əm)
Appearance	Metallic
Promethium in the periodic table
- ↑ Pm ↓ Np Neodymium ← Promethium → Samarium
Atomic number	61
Standard atomic weight (Ar)
Group, block	n/a; f-block
Period	period 6
Electron configuration	[Xe] 4f5 6s2
per shell	2, 8, 18, 23, 8, 2
Physical properties
Phase	Solid
Melting point	1315 K ​(1042 °C, ​1908 °F)
Boiling point	3273 K ​(3000 °C, ​5432 °F)
Density near r.t.	7.26 g/cm3
Heat of fusion	7.13 kJ/mol
Heat of	289 kJ/mol
Atomic properties
Oxidation states	+2, +3
energies	1st: 540 kJ/mol 2nd: 1050 kJ/mol 3rd: 2150 kJ/mol
Atomic radius	empirical: 183 pm
Covalent radius	199 pm
Miscellanea
Crystal structure	​
Thermal expansion	9.0 µm/(m·K) (at room temperature)
Thermal conductivity	17.9 W/(m·K)
Electrical resistivity	0.75 Ω·m (at 20 °C) (estimated)
Magnetic ordering	paramagnetic
Young's modulus	α form: est. 46 GPa
Shear modulus	α form: est. 18 GPa
Bulk modulus	α form: est. 33 GPa
Poisson ratio	α form: est. 0.28 GPa
CAS Registry Number	7440-12-2
History
Discovery	Chien Shiung Wu, Emilio Segrè, Hans Bethe (1942)
First isolation	Charles D. Coryell, Jacob A. Marinsky, Lawrence E. Glendenin (1945)
Named by	Grace Mary Coryell (1945)

Promethium is an extremely radioactive lanthanide. It is one of two elements with no stable isotopes before bismuth, the other being technetium.

Properties

Chemical

The chemistry of promethium is very similar to that of other lanthanides.

Availability

Promethium is extremely hard to find, but some sellers do exist. It's very expensive.

Isolation

To do

Projects

• Element collection

Handling

Safety

To do

Storage

To do

Disposal

To do