HOLMIUM

Introduction

Atomic Number: 67
Group: None
Atomic Weight: 164.93032
Period: 6
CAS Number: 7440-60-0

Classification

Chalcogen
Halogen
Noble Gas
Lanthanoid
Actinoid
Rare Earth Element
Platinum Group Metal
Transuranium
No Stable Isotopes
Solid
Liquid
Gas
Solid (Predicted)

Description • Uses/Function

The spectral absorption bands of holmium were noticed in 1878 by the Swiss chemists Delafontaine and Soret, who announced the existence of an “ElementX”. Cleve, of Sweden, later independently discovered the element while working on erbia earth. The element is named after Cleve’s native city. Pureholmia, the yellow oxide, was prepared by Homberg in 1911. Holmium occurs in gadolinite, monazite, and in other rare-earth minerals. It iscommercially obtained from monazite, occurring in that mineral to the extent of about 0.05%. It has been isolated by the reduction of its anhydrouschloride or fluoride with calcium metal. Pure holmium has a metallic to bright silver luster. It is relatively soft and malleable, and is stable in dry airat room temperature, but rapidly oxidizes in moist air and at elevated temperatures. The metal has unusual magnetic properties. Few uses have yet beenfound for the element. The element, as with other rare earths, seems to have a low acute toxic rating. Natural holmium is not radioactive. Holmiumhas 46 other isotopes known, all of which are radioactive. The price of 99.9% holmium metal is about $15/g. 1

Physical Properties

Melting Point:2*  1474 °C = 1747.15 K = 2685.2 °F
Boiling Point:2* 2700 °C = 2973.15 K = 4892 °F
Sublimation Point:2 
Triple Point:2 
Critical Point:2 
Density:3  8.80 g/cm3

* - at 1 atm

Electron Configuration

Electron Configuration:  *[Xe] 6s2 4f11
Block: f
Highest Occupied Energy Level: 6
Valence Electrons: 2

Quantum Numbers:

n = 4
ℓ = 3
m = 0
ms = -½

Bonding

Electronegativity (Pauling scale):4 1.23
Electropositivity (Pauling scale): 2.77

Ionization Potential   eV 5  kJ/mol  
1 6.0215    581.0
Ionization Potential   eV 5  kJ/mol  
2 11.8    1138.5
Ionization Potential   eV 5  kJ/mol  
3 22.84    2203.7
4 42.5    4100.6

Thermochemistry

Specific Heat: 0.165 J/g°C 6 = 27.214 J/mol°C = 0.039 cal/g°C = 6.504 cal/mol°C
Thermal Conductivity: 16.2 (W/m)/K, 27°C 7
Heat of Fusion: 12.2 kJ/mol 8 = 74.0 J/g
Heat of Vaporization: 241 kJ/mol 9 = 1461.2 J/g
State of Matter Enthalpy of Formation (ΔHf°)10 Entropy (S°)10 Gibbs Free Energy (ΔGf°)10
(kcal/mol) (kJ/mol) (cal/K) (J/K) (kcal/mol) (kJ/mol)
(s) 0 0 18.0 75.312 0 0
(g) 71.9 300.8296 46.72 195.47648 63.3 264.8472

Isotopes

Nuclide Mass 11 Half-Life 11 Nuclear Spin 11 Binding Energy
140Ho 139.96854(54)# 6(3) ms 8+# 1,114.83 MeV
141Ho 140.96310(54)# 4.1(3) ms (7/2-) 1,122.90 MeV
142Ho 141.95977(54)# 400(100) ms (6 to 9) 1,140.28 MeV
143Ho 142.95461(43)# 300# ms [>200 ns] 11/2-# 1,148.35 MeV
144Ho 143.95148(32)# 0.7(1) s 1,156.43 MeV
145Ho 144.94720(32)# 2.4(1) s (11/2-) 1,173.81 MeV
146Ho 145.94464(21)# 3.6(3) s (10+) 1,181.88 MeV
147Ho 146.94006(3) 5.8(4) s (11/2-) 1,189.95 MeV
148Ho 147.93772(14) 2.2(11) s (1+) 1,207.34 MeV
149Ho 148.933775(20) 21.1(2) s (11/2-) 1,215.41 MeV
150Ho 149.933496(15) 76.8(18) s 2- 1,223.48 MeV
151Ho 150.931688(13) 35.2(1) s 11/2(-) 1,231.55 MeV
152Ho 151.931714(15) 161.8(3) s 2- 1,239.63 MeV
153Ho 152.930199(6) 2.01(3) min 11/2- 1,247.70 MeV
154Ho 153.930602(9) 11.76(19) min 2- 1,255.77 MeV
155Ho 154.929103(19) 48(1) min 5/2+ 1,273.15 MeV
156Ho 155.92984(5) 56(1) min 4- 1,281.23 MeV
157Ho 156.928256(26) 12.6(2) min 7/2- 1,289.30 MeV
158Ho 157.928941(29) 11.3(4) min 5+ 1,297.37 MeV
159Ho 158.927712(4) 33.05(11) min 7/2- 1,305.44 MeV
160Ho 159.928729(16) 25.6(3) min 5+ 1,313.51 MeV
161Ho 160.927855(3) 2.48(5) h 7/2- 1,321.58 MeV
162Ho 161.929096(4) 15.0(10) min 1+ 1,329.65 MeV
163Ho 162.9287339(27) 4570(25) a 7/2- 1,337.73 MeV
164Ho 163.9302335(30) 29(1) min 1+ 1,336.48 MeV
165Ho 164.9303221(27) STABLE 7/2- 1,344.55 MeV
166Ho 165.9322842(27) 26.83(2) h 0- 1,352.62 MeV
167Ho 166.933133(6) 3.003(18) h 7/2- 1,360.70 MeV
168Ho 167.93552(3) 2.99(7) min 3+ 1,368.77 MeV
169Ho 168.936872(22) 4.72(10) min 7/2- 1,376.84 MeV
170Ho 169.93962(5) 2.76(5) min 6+# 1,384.91 MeV
171Ho 170.94147(64) 53(2) s 7/2-# 1,383.67 MeV
172Ho 171.94482(43)# 25(3) s 1,391.74 MeV
173Ho 172.94729(43)# 10# s 7/2-# 1,399.81 MeV
174Ho 173.95115(54)# 8# s 1,398.56 MeV
175Ho 174.95405(64)# 5# s 7/2-# 1,406.64 MeV
Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses. 11

Abundance

Earth - Source Compounds: phosphates 12
Earth - Seawater: 0.00000022 mg/L 13
Earth -  Crust:  1.3 mg/kg = 0.00013% 13
Earth -  Total:  80 ppb 14
Mercury -  Total:  61 ppb 14
Venus -  Total:  84 ppb 14
Chondrites - Total: 0.076 (relative to 106 atoms of Si) 15

Compounds

Safety Information


Material Safety Data Sheet - ACI Alloys, Inc.

For More Information

External Links:

Magazines:
(1) Folger, Tim. The Secret Ingredients of Everything. National Geographic, June 2011, pp 136-145.

Sources

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:15.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(4) - Dean, John A. Lange's Handbook of Chemistry, 11th ed.; McGraw-Hill Book Company: New York, NY, 1973; p 4:8-4:149.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:133.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(8) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(10) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:4-9:94.
(11) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(12) - Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change, 4th ed.; McGraw-Hill Higher Education: Boston, MA, 2006, p 965.
(13) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.
(14) - Morgan, John W. and Anders, Edward, Proc. Natl. Acad. Sci. USA 77, 6973-6977 (1980)
(15) - Brownlow, Arthur. Geochemistry; Prentice-Hall, Inc.: Englewood Cliffs, NJ, 1979, pp 15-16.