Holmium Ho (Element 67) of Periodic Table

67 Ho (Holmium)

Holmium has a metallic to bright silver luster, soft and Malleable.
It is rapidly oxidizes in moist air and at elevated temperatures, But stable in dry air at room temperature (20 ^oC)

Identity
CAS Number: CAS7440-60-0
CID Number:  CID23988
DOT Numbers:  3089

Basic Properties of Holmium

Pronunciation:  Hol-mee-am
Appearance:  Silvery white
Mass Number:  164
Standard Atomic weight:  164.930 g/mol
Atomic number (Z):  67
Electrons: 67
Protons:  67
Neutrons:  97
Period:  6
Block:  f
Element category:  Lanthanide
Electrons per shell:  K2, L8, M18, N29, O8, P2
Electron configuration:  1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰5s²5p⁶4f¹¹6s² 

Thermal Properties of Holmium

Phase:  Solid
Melting point:  1734 K (1461 ^oC, 2662 ^oF)
Boiling point:   2873 K (2600 ^oC, 4712 ^oF)
Fusion heat:  17 kJ/mol
Vaporization heat:  251 kJ/mol
Molar heat capacity:  27.15 J/(mol.K)
Thermal expansion:  poly: 11.2 μm/(m∙K)
Thermal conductivity:  16.2 W/(m∙K)
Neel  Point:  132 K

Electrical properties of Holmium

Electrical conductivity: 1.1 x10⁶ S/m
s Electrical resistivity:  poly: 0.814 μΩ∙m
s Electrical type:  Conductor
Curie point:  20 K

Magnetic Properties of Holmium

Magnetic type:  Paramagnetic
s Volume magnetic susceptibility:  0.0482845
Mass magnetic susceptibility:  5490×10^-9 m³/kg
Molar magnetic susceptibility:  905.467×10^-9 m³/mol

Physical Properties of Holmium

Density:  8.79 g/cm³ (In solid)  8.34 g/cm³ (In Liquid)
Molar volume:  0.00001875 m³/mol
Young’s modulus:  64.8 GPa
Shear modulus:  26.3 GPa
Mohs Hardness:  1.65
Bulk modulus:  40.2 GPa
Poisson ratio:  0.231
Vicker hardness:  410-600 MPa
Brinell hardness:  500-1250 MPa
Sound Speed:  2760 m/s

Atomic Properties of Holmium

Oxidation states:  3, 2, 1
Valence Electrons:  4f¹¹ 6s²
Ion charge:  Ho³⁺
Ionization energies:  1st: 581.0 kJ.mol 2nd: 1140 kJ/mol 3rd: 2204 kJ/mol
Ionic radius:   90.1 pm
Atomic radius:  216 pm (Van der Waals)
Covalent radius:  192±7 pm
Filling Orbital:  4f¹¹
Crystal structure:  Hexagonal close-packed
Lattice angles:  π/2, π/2, π/3
Lattice constant:  357.73, 357.73, 561.6 pm
Grid parameters:  a=3.577 Å, c=5.616 Å
Attitude c/a:  1.570
Space Group Name:  P6₃/mmc
Space Group Number:  194

Reactivity of Holmium

Electronegativity:  pauling scale: 1.23
Valence:  +3
Electron affinity:  50 kJ/mol

Nuclear Properties of Holmium

Half Life:  Stable (Infinity)
Lifetime:  Stable (Infinity)
Quantum Number:  ⁴I_15/2
Neutron cross section (Brans):  65
Neutron Mass Absorption:  0.015
Isotopes:  163_Ho 164_Ho 165_Ho 166_Ho 167_Ho

Isotope	Abundance (%)	Atomic Mass g/mol	Half Life (t1/2)
163Ho	Syn	–	4570 y
164Ho	Syn	–	29 min
165Ho	100	164.93	Stable
166Ho	Syn	–	26.763 h
167Ho	Syn	–	3.1 h

Chemical Reactions

Holmium metal tarnishes slowly in air and burns readily to form a holmium (lll) oxide:
4 Ho + 3 O₂ → 2 Ho₂O₃
Reacts slowly with cold water and rapidly with hot water (form holmium hydroxide and hydrogen gas):
2 Ho (s) + 6 H₂O (l) → 2 Ho(OH)₃ (aq) + 3 H₂ (g)
The metal reacts with all Halogens to form Dysprosium (lll) halides:
2 Ho (s) + 3 F₂ (g) → 2 HoF₃ (s)  [pink]  (Holmium (lll) fluoride)
2 Ho (s) + 3 Cl₂ (g) → 2 HoCl₃ (s)  [yellow]  (Holmium (lll) chloride)
2 Ho (s) + 3 Br₂ (g) → 2 HoBr₃ (s)  [yellow]  (Holmium (lll) bromide)
2 Ho (s) + 3 I₂ (g)  →  2 HoI₃ (s)     [yellow]  (Holmium (lll) iodide)
Dissolves readily in dilute sulfuric acid to form Solutions containing Holmium (lll) ions (yellow):
2 Ho (s) + 3 H₂SO₄ (aq) → 2 Ho³⁺ (aq) + 3 SO₄²⁻ (aq) + 3 H₂ (g)

Holmium History

Naming:  From Holmia (Greek name of Sweden)
Discovery:  Jacques-Louis Soret (1878)

Holmium Uses

AHolmium can readily absorb neutrons, So it is used As control-rods in nuclear reactors to keep a chain reaction under control.
Its alloys are used as a flux concentrator for high magnetic fields.

Biological role: It is Low-toxic, But it should be handled with care.

Abundance of Holmium

Holman’s Chief ores are monazite and bastnasite.
It is extracted from those ores that are processed to extract yttrium.  
It is obtained by ion exchange and solvent extraction.

Annual world production is around 10 tons.
5×10^-8% (In Universe)
5.9×10^-6% (In Meteorites)
0.00012% (In Earth’s Crust)
2.2×10^-11% (In Oceans)

World’s Top 3 producers of Holmium

1) China
2) Russia
3) Malaysia

World’s Top 3 Reserve holders of Holmium

1) China
2) CIS Countries (inc. Russia)
3) USA

#holmiun

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