Pm - Promethium - periodic table of the elements

Promethium was found in minerals in 1926 by Harris and Hopkins in the US and independently by Rolla and Fernando in Italy. Synthetic promethium was produced by H. B. Law in 1941. Promethium is very rare.

Atomic number	-	61		Density	g/mL	6	.475
Atomic weight	u	145		Melting point	K	1441
Bonding radius	A	1	.63	Boiling point	K	2733
Atomic radius	A	2	.62	Heat of vaporization	kJ/mol	-
Ionization Potential	V	5	.554	Heat of fusion	kJ/mol	-
Electronegativity	-	1	.13	Specific heat	J/gK	-
The oxide is mildly basic.				Crystal are hexagonal.
Electron configuration: [Xe] 4f⁵ 6s²

Other elements of the periodic table

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba La * Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Ac ** Rf Db Sg Bh Hs Mt 110 111 112 113

Lanthanides* Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Actinides ** Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr