Europium

Europium (Eu)

Soft silvery metallic element belonging to the lanthanoids. Eu-151 and Eu-153 are the only two stable isotopes, both of which are Neutron absorbers. Discovered in 1889 by Sir William Crookes.
Atomic Number63
Atomic Weight151.964
Mass Number153
Group
Period6
Blockf
Protons63 p+
Neutrons90 n0
Electrons63 e-
Eu-Block.jpg Animated Bohr Model of Eu (Europium) Enhanced Bohr Model of Eu (Europium) Bohr Model: Eu (Europium) Orbital Diagram of Eu (Europium)

Properties

Atomic Radius
185 pm
Molar Volume
Covalent Radius
168 pm
Metallic Radius
Ionic Radius
117 pm
Crystal Radius
131 pm
Van der Waals Radius
235 pm
Density
5.24 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy
5.670385 eV/particle
Heat of Vaporization
176 kJ/mol
Heat of Fusion
Heat of Formation
177.4 kJ/mol
Electrons
Electron Shells2, 8, 18, 25, 8, 2
Valence Electrons3
Electron Configuration[Xe] 4f7 6s2
Oxidation States0, 2, 3
Electronegativity
Electrophilicity
1.1104548254099753 eV/particle
Phases
PhaseSolid
Gas Phase
Boiling Point
1,802.15 K
Melting Point
1,095.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color
Silver
Appearance
Refractive Index
Thermodynamic Properties
Thermal Conductivity
13.9 W/(m K)
Thermal Expansion
0.000035 1/K
Molar Heat Capacity
27.66 J/(mol K)
Specific Heat Capacity
0.182 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
TypeConductor
Electrical Conductivity
1.1 MS/m
Electrical Resistivity
0.0000009 m Ω
Superconducting Point
1.8 K
Magnetism
Typeparamagnetic
Magnetic Susceptibility (Mass)
0.000000276 m³/Kg
Magnetic Susceptibility (Molar)
0.000000041942 m³/mol
Magnetic Susceptibility (Volume)
0.0014473
Magnetic Ordering
Curie Point
Neel Point
90.5 K
Structure
Crystal StructureBody Centered Cubic (BCC)
Lattice Constant
4.61 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties
Hardness
Bulk Modulus
8.3 GPa
Shear Modulus
7.9 GPa
Young Modulus
18 GPa
Poisson Ratio
0.15
Speed of Sound
Classification
CategoryLanthanides, Lanthanides
CAS Group
IUPAC Group
Glawe Number17
Mendeleev Number25
Pettifor Number18
Geochemical Classrare earth & related
Goldschmidt Classlitophile
Other
Gas Basicity
Dipole Polarizability
184 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
4,570
Neutron Mass Absorption
0.6
Quantum Numbers8S7/2
Space Group229 (Im_3m)

Isotopes of Europium

Stable Isotopes2
Unstable Isotopes39
Radioactive Isotopes39

130Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
129.964022 ± 0.000578 Da
Mass Number130
G-Factor
Half Life
1 ± 0.4 ms
Spin1
Quadrupole Moment
Discovery Year2004
Parity+

130Eu Decay Modes
Decay ModeIntensity
p (proton emission)100%
β+ (β+ decay; β+ = ϵ + e+)%
β+ p (β+-delayed proton emission)%

131Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
130.957634 ± 0.000429 Da
Mass Number131
G-Factor
Half Life
17.8 ± 1.9 ms
Spin3/2
Quadrupole Moment
Discovery Year1998
Parity+

131Eu Decay Modes
Decay ModeIntensity
p (proton emission)89%
β+ (β+ decay; β+ = ϵ + e+)%
β+ p (β+-delayed proton emission)%

132Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
131.954696 ± 0.000429 Da
Mass Number132
G-Factor
Half Life
Spin1
Quadrupole Moment
Discovery Year
Parity+

132Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)%
β+ p (β+-delayed proton emission)%
p (proton emission)0%

133Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
132.94929 ± 0.00032 Da
Mass Number133
G-Factor
Half Life
Spin5/2
Quadrupole Moment
Discovery Year
Parity+

133Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)%
β+ p (β+-delayed proton emission)%

134Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
133.946537 ± 0.000322 Da
Mass Number134
G-Factor
Half Life
500 ± 200 ms
Spin
Quadrupole Moment
Discovery Year1989
Parity

134Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)%

135Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
134.94187 ± 0.00021 Da
Mass Number135
G-Factor
Half Life
1.5 ± 0.2 s
Spin5/2
Quadrupole Moment
Discovery Year1989
Parity+

135Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)%

136Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
135.93962 ± 0.00021 Da
Mass Number136
G-Factor
Half Life
3.3 ± 0.3 s
Spin6
Quadrupole Moment
Discovery Year1987
Parity+

136Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.09%

137Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
136.935430719 ± 0.0000047 Da
Mass Number137
G-Factor
Half Life
8.4 ± 0.5 s
Spin5/2
Quadrupole Moment
Discovery Year1982
Parity+

137Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

138Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
137.933709 ± 0.00003 Da
Mass Number138
G-Factor
0.88333333333333 ± 0.11666666666667
Half Life
Spin2
Quadrupole Moment
Discovery Year1982
Parity-

138Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)%

139Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
138.929792307 ± 0.000014117 Da
Mass Number139
G-Factor
1.1090909090909 ± 0.14545454545455
Half Life
17.9 ± 0.6 s
Spin11/2
Quadrupole Moment
Discovery Year1975
Parity

139Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

140Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
139.928087633 ± 0.000055328 Da
Mass Number140
G-Factor
1.362 ± 0.013
Half Life
1.51 ± 0.02 s
Spin1
Quadrupole Moment
Discovery Year1982
Parity+

140Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
e+ (positron emission)95.1%
ϵ (electron capture)4.9%

141Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
140.924931734 ± 0.000013568 Da
Mass Number141
G-Factor
1.3944 ± 0.0032
Half Life
40.7 ± 0.7 s
Spin5/2
Quadrupole Moment
0.85 ± 0.04
Discovery Year1977
Parity+

141Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

142Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
141.923446719 ± 0.000032268 Da
Mass Number142
G-Factor
1.532 ± 0.019
Half Life
2.36 ± 0.1 s
Spin1
Quadrupole Moment
0.12 ± 0.05
Discovery Year1966
Parity+

142Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
e+ (positron emission)89.9%
ϵ (electron capture)10.1%

143Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
142.920298678 ± 0.000011793 Da
Mass Number143
G-Factor
1.4656 ± 0.0032
Half Life
2.59 ± 0.02 m
Spin5/2
Quadrupole Moment
0.51 ± 0.03
Discovery Year1965
Parity+

143Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

144Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
143.918819481 ± 0.00001158 Da
Mass Number144
G-Factor
1.888 ± 0.013
Half Life
10.2 ± 0.1 s
Spin1
Quadrupole Moment
0.1 ± 0.03
Discovery Year1965
Parity+

144Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

145Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
144.916272659 ± 0.000003285 Da
Mass Number145
G-Factor
1.5932 ± 0.0028
Half Life
5.93 ± 0.04 d
Spin5/2
Quadrupole Moment
0.29 ± 0.02
Discovery Year1951
Parity+

145Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

146Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
145.917210852 ± 0.000006451 Da
Mass Number146
G-Factor
0.3555 ± 0.00275
Half Life
4.61 ± 0.03 d
Spin4
Quadrupole Moment
-0.18 ± 0.06
Discovery Year1957
Parity-

146Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

147Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
146.91675244 ± 0.000002758 Da
Mass Number147
G-Factor
1.486 ± 0.0032
Half Life
24.1 ± 0.6 d
Spin5/2
Quadrupole Moment
0.55 ± 0.03
Discovery Year1951
Parity+

147Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)0.0022%

148Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
147.918091288 ± 0.000010693 Da
Mass Number148
G-Factor
0.4668 ± 0.002
Half Life
54.5 ± 0.5 d
Spin5
Quadrupole Moment
0.35 ± 0.06
Discovery Year1951
Parity-

148Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
α (α emission)9.4%

149Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
148.917936875 ± 0.00000419 Da
Mass Number149
G-Factor
1.4224 ± 0.0024
Half Life
93.1 ± 0.4 d
Spin5/2
Quadrupole Moment
0.75 ± 0.02
Discovery Year1959
Parity+

149Eu Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

150Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
149.919707092 ± 0.000006688 Da
Mass Number150
G-Factor
0.5404 ± 0.0022
Half Life
36.9 ± 0.9 y
Spin5
Quadrupole Moment
1.13 ± 0.05
Discovery Year1950
Parity-

150Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

151Eu

AbundanceRadioactive ☢️
47.81 ± 0.06
Relative Atomic Mass
150.919856606 ± 0.000001251 Da
Mass Number151
G-Factor
1.3854 ± 0.001
Half Life
4.6 ± 1.2 Ey
Spin5/2
Quadrupole Moment
0.903 ± 0.01
Discovery Year1933
Parity+

151Eu Decay Modes
Decay ModeIntensity
α (α emission)100%

152Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
151.92175098 ± 0.000001252 Da
Mass Number152
G-Factor
-0.64513333333333 ± 0.00056666666666667
Half Life
13.517 ± 0.006 y
Spin3
Quadrupole Moment
2.72 ± 0.03
Discovery Year1938
Parity-

152Eu Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)72.08%
β (β decay)27.92%

153Eu

Abundance
52.19 ± 0.06
Relative Atomic Mass
152.921236789 ± 0.000001257 Da
Mass Number153
G-Factor
0.61176 ± 0.00044
Half Life
Spin5/2
Quadrupole Moment
2.41 ± 0.02
Discovery Year1933
Parity+

154Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
153.922985699 ± 0.000001275 Da
Mass Number154
G-Factor
-0.66666666666667 ± 0.002
Half Life
8.592 ± 0.003 y
Spin3
Quadrupole Moment
2.85 ± 0.1
Discovery Year1947
Parity-

154Eu Decay Modes
Decay ModeIntensity
β (β decay)99.982%
ϵ (electron capture)0.018%

155Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
154.922899847 ± 0.000001343 Da
Mass Number155
G-Factor
0.6064 ± 0.0008
Half Life
4.742 ± 0.008 y
Spin5/2
Quadrupole Moment
2.5 ± 0.3
Discovery Year1947
Parity+

155Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

156Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
155.924762976 ± 0.000003791 Da
Mass Number156
G-Factor
0
Half Life
15.19 ± 0.08 d
Spin0
Quadrupole Moment
0
Discovery Year1947
Parity+

156Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

157Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
156.925432556 ± 0.000004545 Da
Mass Number157
G-Factor
0.6 ± 0.008
Half Life
15.18 ± 0.03 h
Spin5/2
Quadrupole Moment
2.6 ± 0.3
Discovery Year1951
Parity+

157Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

158Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
157.927782192 ± 0.000002181 Da
Mass Number158
G-Factor
1.44 ± 0.02
Half Life
45.9 ± 0.2 m
Spin1
Quadrupole Moment
0.66 ± 0.14
Discovery Year1951
Parity-

158Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

159Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
158.929099512 ± 0.000004637 Da
Mass Number159
G-Factor
0.552 ± 0.008
Half Life
18.1 ± 0.1 m
Spin5/2
Quadrupole Moment
2.7 ± 0.3
Discovery Year1961
Parity+

159Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

160Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
159.931836982 ± 0.00000097 Da
Mass Number160
G-Factor
Half Life
42.6 ± 0.5 s
Spin5
Quadrupole Moment
Discovery Year1973
Parity-

160Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

161Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
160.933663991 ± 0.000011164 Da
Mass Number161
G-Factor
Half Life
26.2 ± 2.3 s
Spin5/2
Quadrupole Moment
Discovery Year1986
Parity+

161Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

162Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
161.936958329 ± 0.00000141 Da
Mass Number162
G-Factor
Half Life
Spin1
Quadrupole Moment
Discovery Year1987
Parity+

162Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

163Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
162.93926551 ± 0.00000097 Da
Mass Number163
G-Factor
Half Life
7.7 ± 0.4 s
Spin5/2
Quadrupole Moment
Discovery Year2007
Parity+

163Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

164Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
163.942852943 ± 0.000002219 Da
Mass Number164
G-Factor
Half Life
4.16 ± 0.19 s
Spin3
Quadrupole Moment
Discovery Year2007
Parity-

164Eu Decay Modes
Decay ModeIntensity
β (β decay)100%

165Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
164.94554007 ± 0.000005596 Da
Mass Number165
G-Factor
Half Life
2.53 ± 0.25 s
Spin5/2
Quadrupole Moment
Discovery Year2007
Parity+

165Eu Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

166Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
165.949813 ± 0.000107 Da
Mass Number166
G-Factor
0
Half Life
1.24 ± 0.12 s
Spin0
Quadrupole Moment
0
Discovery Year2007
Parity-

166Eu Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

167Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
166.953011 ± 0.000429 Da
Mass Number167
G-Factor
Half Life
1.33 ± 0.51 s
Spin5/2
Quadrupole Moment
Discovery Year2012
Parity+

167Eu Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

168Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
167.957863 ± 0.000429 Da
Mass Number168
G-Factor
Half Life
200 ± 100 ms
Spin6
Quadrupole Moment
Discovery Year2012
Parity-

168Eu Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

169Eu

AbundanceRadioactive ☢️
Relative Atomic Mass
168.961717 ± 0.000537 Da
Mass Number169
G-Factor
Half Life
Spin5/2
Quadrupole Moment
Discovery Year2018
Parity+

169Eu Decay Modes
Decay ModeIntensity
β (β decay)%

170Eu

Abundance
Relative Atomic Mass
169.96687 ± 0.000537 Da
Mass Number170
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

170Eu Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%

History

Europium was first found by Paul Émile Lecoq de Boisbaudran in 1890. In 1896, French chemist Eugène-Antole Demarçay identified spectroscopic lines in ‘samarium' caused by europium. He successfully isolated europium in 1901 using repeated crystallizations of samarium magnesium nitrate. Europium was named after Europe

DiscoverersEugène Demarçay
Discovery LocationFrance
Discovery Year1901
Etymology (Name Origin)Named for the continent of Europe.
Pronunciationyoo-RO-pi-em (English)
Europium is considered to be mildly toxic
Europium is the most reactive rare earth element

Uses

Europium is used in the manufacture of fluorescent glass. It is also used in the anti-counterfeiting phosphors in Euro banknotes. Europium-doped plastic has been used as a laser material. Europium isotopes are good neutron absorbers and are used in nuclear reactor control rods. Used with yttrium oxide to make red phosphors for color televisions.

Sources

Obtained from monazite sand, which is a mixture of phosphates of calcium, thorium, cerium, and most other rare earths.

Abundance
Abundance in Earth's crust
Abundance in Oceans
0.00000013 mg/L
Abundance in Human Body
Abundance in Meteor
0.0000059 %
Abundance in Sun
0.00000005 %
Abundance in Universe
0.00000005 %

Nuclear Screening Constants

1s1.2391
2p4.282
2s16.5292
3d13.7472
3p19.716
3s20.1318
4d34.0592
4f38.68
4p31.1252
4s30.132
5p46.445
5s44.41
6s54.8784