Er - Erbium

A rare earth metal, which was discovered by Mosander in 1842.

Atomic number - 68 Density g/mL 9 .05
Atomic weight u 167 .26 Melting point K 1795
Bonding radius A 1 .57 Boiling point K 3136
Atomic radius A 2 .45 Heat of vaporization kJ/mol 261
Ionization Potential V 6 .101 Heat of fusion kJ/mol 19 .9
Electronegativity - 1 .24 Specific heat J/gK 0 .17
The oxide is weak base.
Crystal are hexagonal.

Electron config. : [Xe] 4f12 6s2


Isotopes of Er: Click mass number for decay process, product for element page.

 
146
1.7 sec
EC/ECp,7.000
Ho-146/Dy-145
145.95190
147
2.5 sec
EC/ECp,9.100
Ho-147/Dy-146
146.94943
148
4.6 sec
EC,6.800 MeV
Ho-148
147.94439
149
4 sec
EC/ECp,7.700
Ho-149/Dy-148
148.94213
150
18.5 sec
EC,4.108 MeV
Ho-150
149.93776
151
23.5 sec
EC,5.400 MeV
Ho-151
150.93741
152
10.3 sec
a/EC,4.934
Dy-148/Ho-152
151.93508
153
37.1 sec
a/EC,4.803
Dy-149/Ho-153
152.93509
154
3.73 min
a/EC,2.032
Dy-150/Ho-154
153.93277
154a
39 nsec
a,7.305 MeV
Dy-150
153.93602
155
5.3 min
a/EC,3.840
Dy-151/Ho-155
154.93320
156
19.5 min
a/EC,1.370
Dy-152/Ho-156
155.93118
157
18.65 min
a/EC,3.500
Dy-153/Ho-157
156.93194
158
2.29 hr
EC,4.410 MeV
Ho-158
157.92990
159
36 min
EC,2.769 MeV
Ho-159
158.93068
160
28.58 hr
EC,3.350 MeV
Ho-160
159.92908
161
3.21 hr
EC,1.956 MeV
Ho-161
160.93000
162 0.14%

Stable

161.92877
163
75.0 min
EC,1.210 MeV
Ho-163
162.93002
164 1.61%

Stable

163.92919
165
10.36 hr
EC,1.394 MeV
Ho-165
164.93072
166 33.6%

Stable

165.93029
167 22.95%

Stable

166.93204
168 26.8%

Stable

167.93236
169
9.40 da
B-,2.124 MeV
Tm-169
168.93458
170 14.9%

Stable

169.93546
171
7.516 hr
B-,1.490 MeV
Tm-171
170.93802
172
49.3 hr
B-,1.479 MeV
Tm-172
171.93935
173
1.4 min
B-,2.600 MeV
Tm-173
172.94239
174
3.3 min
B-,1.800 MeV
Tm-174
173.94406
MASS abund.
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass