Eu - Europium

Discovered by Demarçay in 1901.

Atomic number - 63 Density g/mL 5 .26
Atomic weight u 151 .96 Melting point K 1090
Bonding radius A 1 .85 Boiling point K 1870
Atomic radius A 2 .56 Heat of vaporization kJ/mol 143 .5
Ionization Potential V 5 .67 Heat of fusion kJ/mol 9 .21
Electronegativity - 1 .2 Specific heat J/gK 0 .18
The oxide is mildly basic.
Crystal are body centered cubic.

Electron config. : [Xe] 4f7 6s2


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


134
0.5 sec
EC/ECp,5.400
Sm-134/Pm-133
133.94566
135
1.5 sec
EC/ECp,8.700
Sm-135/Pm-134
134.94170
136
3.3 sec
EC/ECp,10.400
Sm-136/Pm-135
135.93945
137
11 sec
EC,7.500 MeV
Sm-137
136.93515
138
12.1 sec
EC,9.200 MeV
Sm-138
137.93344
139
17.9 sec
EC,6.700 MeV
Sm-139
138.92979
140
1.51 sec
EC,8.400 MeV
Sm-140
139.92807
140a
125 msec
EC,8.585 MeV
Sm-140
139.92828
141
41.4 sec
EC,5.550 MeV
Sm-141
140.92443
142
2.4 sec
EC,7.640 MeV
Sm-142
141.92340
143
2.63 min
EC,5.275 MeV
Sm-143
142.92028
144
10.2 sec
EC,6.315 MeV
Sm-144
143.91877
145
5.93 da
EC,2.660 MeV
Sm-145
144.91626
146
4.59 da
EC,3.878 MeV
Sm-146
145.91720
147
24.1 da
a/EC,1.722
Pm-143/Sm-147
146.91674
148
54.5 da
a/EC,3.107
Pm-144/Sm-148
147.91815
149
93.1 da
EC,1.071 MeV
Sm-149
148.91792
150
36.9 yr
EC,2.261 MeV
Sm-150
149.91969
150a
12.8 hr
EC,2.303 MeV
Sm-150
149.91974
151 47.8%

Stable

150.91984
152
13.537 yr
B-/EC,1.874
Gd-152/Sm-152
151.92174
152a
9.3116 hr
EC,1.920 MeV
Sm-152
151.92178
153 52.2%

Stable

152.92122
154
8.593 yr
B-/EC,1.969
Gd-154/Sm-154
153.92297
155
4.7611 yr
B-,1.627 MeV
Gd-155
154.92288
156
15.19 da
B-,2.451 MeV
Gd-156
155.92475
157
15.18 hr
B-,1.363 MeV
Gd-157
156.92541
158
45.9 min
B-,3.490 MeV
Gd-158
157.92784
159
18.1 min
B-,2.514 MeV
Gd-159
158.92908
160
38 sec
B-,4.580 MeV
Gd-160
159.93196
161
26 sec
B-,3.700 MeV
Gd-161
160.93365
162
10.6 sec
B-,5.600 MeV
Gd-162
161.93709
MASS abund.
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass