Return
to the Main CHEMystery Page.
Return
to the Periodic Table of the Elements
Element 67 - Holmium (Ho)
From
Holmia
, Latin name for Stockholm; discovered 1879. Like dysprosium, holmium is a metal which can absorb fission-bred neutrons. It is used in nuclear reactors as a burnable poison--i.e., one that burns up while it is keeping a chain reaction from running out of control.
Properties
Atomic Number
:
67
Atomic Weight
:
164.9303
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
6
4d
10
4f
11
5s
2
5p
6
6s
2
Oxidation States
(Bold most stable):
+3
Boiling Point
(K):
2968
Melting Point (K):
1747
Density
(at 300K -- g/cm
3
):
8.80
Atomic Volume (at 300K -- cm
3
/mol)
18.7
Number of stable
isotopes
:
1
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
166 -- 1.2 x 10
3
years --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.58
Atomic Radius (Å):
1.79
First
Ionization Potential
(V):
6.02
Electronegativity
(Pauling's):
1.23
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.165
Heat of Vaporization (kJ/mol):
251.04
Heat of Fusion (kJ/mol):
17.15
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
1.1
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
16.2
Crystal Structure:
Hexagonal
Acid
-
Base
Properties:
Slightly basic