General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Erbium Symbol Er
atomic number 68 Atomic weight 167.26
Density @ 293 K 9.05 g/cm3 Atomic volume 18.4 cm3/mol
Group Rare Earth, Lanthanides discovered 1843


state (s, l, g) s
melting point 1795.2 K boiling point 3173 K
Heat of fusion 19.90 kJ/mol Heat of vaporization 261.0 kJ/mol
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1st ionization energy 588.7 kJ/mole electronegativity 1.24
2nd ionization energy 1151 kJ/mole electron affinity 50 kJ/mole
3rd ionization energy 2194 kJ/mole Specific heat 0.17 J/gK
heat atomization 317 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,30,8,2 electron configuration [Xe] 4f12 6s2
minimum oxidation number 0 maximum oxidation number 3
min. common oxidation no. 0 max. common oxidation no. 3
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Appearance & Characteristics

structure hcp: hexagonal close pkd color silvery-white
uses alloys, photogr. filter toxicity
hardness mohs characteristics


reaction with air vigorous, = Er2O3 reaction with 6M HCl mild, = H2, ErCl3
reaction with 6M HCl mild, = H2, ErCl3 reaction with 15M HNO3 mild, = Er(NO3)3
reaction with 6M NaOH
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Other Forms

number of isotopes 6 hydride(s) ErH2 ErH3
oxide(s) Er2O3 chloride(s) ErCl3


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 176 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 103 pm
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thermal conductivity 14.5 J/m-sec-deg electrical conductivity 14.1 1/mohm-cm
polarizability 22.7 A^3


source Monazite(phosphate),bastnaesite rel. abund. solar system -0.601 log
abundance earth's crust 0.4 log cost, pure 270 $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.