Palladium

Palladium (Pd)

Soft white ductile transition element. Found with some copper and nickel ores. Does not react with oxygen at normal temperatures. Dissolves slowly in hydrochloric acid. Discovered in 1803 by W.H. Wollaston.
Atomic Number46
Atomic Weight106.42
Mass Number106
Group10
Period5
Blockd
Protons46 p+
Neutrons60 n0
Electrons46 e-
Palladium 1-noReflection.jpg Animated Bohr Model of Pd (Palladium) Enhanced Bohr Model of Pd (Palladium) Bohr Model: Pd (Palladium) Orbital Diagram of Pd (Palladium)

Properties

Atomic Radius
140 pm
Molar Volume
Covalent Radius
120 pm
Metallic Radius
128 pm
Ionic Radius
59 pm
Crystal Radius
73 pm
Van der Waals Radius
210 pm
Density
Energy
Proton Affinity
696 kJ/mol
Electron Affinity
Ionization Energy
8.33686 eV/particle
Heat of Vaporization
372.4 kJ/mol
Heat of Fusion
17.24 kJ/mol
Heat of Formation
376.6 kJ/mol
Electrons
Electron Shells2, 8, 18, 18
Valence Electrons4
Electron Configuration[Kr] 4d10
Oxidation States0, 1, 2, 3, 4, 5
Electronegativity
2.2
Electrophilicity
1.273169376998428 eV/particle
Phases
PhaseSolid
Gas Phase
Boiling Point
3,236.15 K
Melting Point
1,827.95 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color
Silver
Appearancesilvery white
Refractive Index
Thermodynamic Properties
Thermal Conductivity
71.8 W/(m K)
Thermal Expansion
0.0000118 1/K
Molar Heat Capacity
25.98 J/(mol K)
Specific Heat Capacity
0.246 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
TypeConductor
Electrical Conductivity
10 MS/m
Electrical Resistivity
0.0000001 m Ω
Superconducting Point
Magnetism
Typeparamagnetic
Magnetic Susceptibility (Mass)
0.0000000657 m³/Kg
Magnetic Susceptibility (Molar)
0.000000006992 m³/mol
Magnetic Susceptibility (Volume)
0.0007899
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal StructureFace Centered Cubic (FCC)
Lattice Constant
3.89 Å
Lattice Anglesπ/2, π/2, π/2
Mechanical Properties
Hardness
4.75 MPa
Bulk Modulus
180 GPa
Shear Modulus
44 GPa
Young Modulus
121 GPa
Poisson Ratio
0.39
Speed of Sound
3,070 m/s
Classification
CategoryTransition metals, Transition metals
CAS GroupVIIIA
IUPAC GroupVIII
Glawe Number65
Mendeleev Number68
Pettifor Number69
Geochemical Classnoble metal
Goldschmidt Classsiderophile
Other
Gas Basicity
673.4 kJ/mol
Dipole Polarizability
26.14 ± 0.1 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
6.9
Neutron Mass Absorption
0.0023
Quantum Numbers1S0
Space Group225 (Fm_3m)

Isotopes of Palladium

Stable Isotopes6
Unstable Isotopes36
Radioactive Isotopes36

90Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
89.95737 ± 0.000429 Da
Mass Number90
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year2016
Parity+

90Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)%
β+ p (β+-delayed proton emission)%
2p (2-proton emission)%

91Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
90.950435 ± 0.000454 Da
Mass Number91
G-Factor
Half Life
32 ± 3 ms
Spin7/2
Quadrupole Moment
Discovery Year1995
Parity+

91Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)3.1%

92Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
91.941192225 ± 0.000370402 Da
Mass Number92
G-Factor
0
Half Life
1.06 ± 0.03 s
Spin0
Quadrupole Moment
0
Discovery Year1994
Parity+

92Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)1.6%

93Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
92.936680426 ± 0.000397221 Da
Mass Number93
G-Factor
Half Life
1.17 ± 0.02 s
Spin9/2
Quadrupole Moment
Discovery Year1994
Parity+

93Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)7.4%

94Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
93.929036286 ± 0.000004602 Da
Mass Number94
G-Factor
0
Half Life
9.1 ± 0.3 s
Spin0
Quadrupole Moment
0
Discovery Year1982
Parity+

94Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.13%

95Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
94.924888506 ± 0.000003253 Da
Mass Number95
G-Factor
Half Life
7.4 ± 0.4 s
Spin9/2
Quadrupole Moment
Discovery Year1980
Parity+

95Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%
β+ p (β+-delayed proton emission)0.23%

96Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
95.918213739 ± 0.000004502 Da
Mass Number96
G-Factor
0
Half Life
122 ± 2 s
Spin0
Quadrupole Moment
0
Discovery Year1980
Parity+

96Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

97Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
96.916471985 ± 0.0000052 Da
Mass Number97
G-Factor
Half Life
3.1 ± 0.09 m
Spin5/2
Quadrupole Moment
Discovery Year1969
Parity+

97Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

98Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
97.912698335 ± 0.00000509 Da
Mass Number98
G-Factor
0
Half Life
17.7 ± 0.4 m
Spin0
Quadrupole Moment
0
Discovery Year1955
Parity+

98Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

99Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
98.911773073 ± 0.000005482 Da
Mass Number99
G-Factor
Half Life
21.4 ± 0.2 m
Spin5/2
Quadrupole Moment
Discovery Year1955
Parity

99Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

100Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
99.908520438 ± 0.000018934 Da
Mass Number100
G-Factor
0
Half Life
3.63 ± 0.09 d
Spin0
Quadrupole Moment
0
Discovery Year1948
Parity+

100Pd Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

101Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
100.908284824 ± 0.000004925 Da
Mass Number101
G-Factor
0.264 ± 0.008
Half Life
8.47 ± 0.06 h
Spin5/2
Quadrupole Moment
Discovery Year1948
Parity+

101Pd Decay Modes
Decay ModeIntensity
β+ (β+ decay; β+ = ϵ + e+)100%

102Pd

Abundance
1.02 ± 0.01
Relative Atomic Mass
101.905632292 ± 0.000000449 Da
Mass Number102
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1935
Parity+

102Pd Decay Modes
Decay ModeIntensity
+ (double β+ decay)%

103Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
102.906111074 ± 0.000000942 Da
Mass Number103
G-Factor
Half Life
16.991 ± 0.019 d
Spin5/2
Quadrupole Moment
Discovery Year1950
Parity+

103Pd Decay Modes
Decay ModeIntensity
ϵ (electron capture)100%

104Pd

Abundance
11.14 ± 0.08
Relative Atomic Mass
103.904030393 ± 0.000001434 Da
Mass Number104
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1935
Parity+

105Pd

Abundance
22.33 ± 0.08
Relative Atomic Mass
104.905079479 ± 0.000001222 Da
Mass Number105
G-Factor
Half Life
Spin5/2
Quadrupole Moment
0.66 ± 0.011
Discovery Year1935
Parity+

106Pd

Abundance
27.33 ± 0.03
Relative Atomic Mass
105.903480287 ± 0.000001186 Da
Mass Number106
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1935
Parity+

107Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
106.905128058 ± 0.000001289 Da
Mass Number107
G-Factor
Half Life
6.5 ± 0.3 My
Spin5/2
Quadrupole Moment
Discovery Year1958
Parity+

107Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

108Pd

Abundance
26.46 ± 0.09
Relative Atomic Mass
107.903891806 ± 0.000001189 Da
Mass Number108
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1935
Parity+

109Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
108.905950576 ± 0.000001195 Da
Mass Number109
G-Factor
Half Life
13.59 ± 0.12 h
Spin5/2
Quadrupole Moment
Discovery Year1937
Parity+

109Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

110Pd

Abundance
11.72 ± 0.09
Relative Atomic Mass
109.905172878 ± 0.000000657 Da
Mass Number110
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year1935
Parity+

110Pd Decay Modes
Decay ModeIntensity
(double β decay)%

111Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
110.907690358 ± 0.000000785 Da
Mass Number111
G-Factor
Half Life
23.56 ± 0.09 m
Spin5/2
Quadrupole Moment
Discovery Year1937
Parity+

111Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

112Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
111.907330557 ± 0.000007027 Da
Mass Number112
G-Factor
0
Half Life
21.04 ± 0.17 h
Spin0
Quadrupole Moment
0
Discovery Year1951
Parity+

112Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

113Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
112.910261912 ± 0.000007458 Da
Mass Number113
G-Factor
Half Life
93 ± 5 s
Spin5/2
Quadrupole Moment
Discovery Year1954
Parity+

113Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

114Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
113.91036943 ± 0.000007459 Da
Mass Number114
G-Factor
0
Half Life
2.42 ± 0.06 m
Spin0
Quadrupole Moment
0
Discovery Year1958
Parity+

114Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

115Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
114.913659333 ± 0.000014543 Da
Mass Number115
G-Factor
Half Life
25 ± 2 s
Spin1/2
Quadrupole Moment
0
Discovery Year1958
Parity

115Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

116Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
115.914297872 ± 0.000007659 Da
Mass Number116
G-Factor
0
Half Life
11.8 ± 0.4 s
Spin0
Quadrupole Moment
0
Discovery Year1970
Parity+

116Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

117Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
116.917955584 ± 0.000007788 Da
Mass Number117
G-Factor
Half Life
4.3 ± 0.3 s
Spin3/2
Quadrupole Moment
Discovery Year1968
Parity+

117Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

118Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
117.919067273 ± 0.000002677 Da
Mass Number118
G-Factor
0
Half Life
1.9 ± 0.1 s
Spin0
Quadrupole Moment
0
Discovery Year1969
Parity+

118Pd Decay Modes
Decay ModeIntensity
β (β decay)100%

119Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
118.923341138 ± 0.000008854 Da
Mass Number119
G-Factor
Half Life
920 ± 80 ms
Spin3/2
Quadrupole Moment
Discovery Year1991
Parity+

119Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

120Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
119.924551745 ± 0.000002464 Da
Mass Number120
G-Factor
0
Half Life
492 ± 33 ms
Spin0
Quadrupole Moment
0
Discovery Year1993
Parity+

120Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)0.7%

121Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
120.928950342 ± 0.0000036 Da
Mass Number121
G-Factor
Half Life
290 ± 1 ms
Spin3/2
Quadrupole Moment
Discovery Year1994
Parity+

121Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)0.8%

122Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
121.930631693 ± 0.000021 Da
Mass Number122
G-Factor
0
Half Life
193 ± 5 ms
Spin0
Quadrupole Moment
0
Discovery Year1994
Parity+

122Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)2.5%

123Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
122.935126 ± 0.0008475 Da
Mass Number123
G-Factor
Half Life
108 ± 1 ms
Spin3/2
Quadrupole Moment
Discovery Year1994
Parity+

123Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)10%

124Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
123.937305 ± 0.000322 Da
Mass Number124
G-Factor
0
Half Life
88 ± 15 ms
Spin0
Quadrupole Moment
0
Discovery Year1997
Parity+

124Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)17%

125Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
124.942072 ± 0.000429 Da
Mass Number125
G-Factor
Half Life
60 ± 6 ms
Spin3/2
Quadrupole Moment
Discovery Year2008
Parity+

125Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)12%

126Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
125.944401 ± 0.000429 Da
Mass Number126
G-Factor
0
Half Life
48.6 ± 0.8 ms
Spin0
Quadrupole Moment
0
Discovery Year2008
Parity+

126Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)22%

127Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
126.949307 ± 0.000537 Da
Mass Number127
G-Factor
Half Life
38 ± 2 ms
Spin11/2
Quadrupole Moment
Discovery Year2010
Parity-

127Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)19%
2n (2-neutron emission)%

128Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
127.952345 ± 0.000537 Da
Mass Number128
G-Factor
0
Half Life
35 ± 3 ms
Spin0
Quadrupole Moment
0
Discovery Year2010
Parity+

128Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%

129Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
128.959334 ± 0.000644 Da
Mass Number129
G-Factor
Half Life
31 ± 7 ms
Spin7/2
Quadrupole Moment
Discovery Year2015
Parity-

129Pd Decay Modes
Decay ModeIntensity
β (β decay)100%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

130Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
129.964863 ± 0.000322 Da
Mass Number130
G-Factor
0
Half Life
Spin0
Quadrupole Moment
0
Discovery Year2018
Parity+

130Pd Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

131Pd

AbundanceRadioactive ☢️
Relative Atomic Mass
130.972367 ± 0.000322 Da
Mass Number131
G-Factor
Half Life
Spin7/2
Quadrupole Moment
Discovery Year2018
Parity-

131Pd Decay Modes
Decay ModeIntensity
β (β decay)%
β n (β-delayed neutron emission)%
2n (2-neutron emission)%

History

Palladium was discovered in 1803, in London, by English chemist William Hyde Wollaston. He examined the residues left from platinum after dissolving it in aqua regia, a concentrated solution of hydrochloric and nitric acids. He then isolated palladium in a series of chemical reactions. Palladium was named after the asteroid Pallas; Pallas was the Greek goddess of wisdom

DiscoverersWilliam Wollaston
Discovery LocationEngland
Discovery Year1803
Etymology (Name Origin)Named after the asteroid, Pallas, discovered in 1803.
Pronunciationpeh-LAY-di-em (English)
Palladium is considered to be of low toxicity
In the late 1800s, palladium was more expensive than platinum

Uses

The largest use of palladium is in catalytic converters in the automobile industry. Finely divided palladium is a good catalyst and is used for hydrogenation and dehydrogenation reactions. The metal is used in dentistry, watch making, and in making surgical instruments and electrical contacts. Used as a substitue for silver in dental items and jewelry. The pure metal is used as the delicate mainsprings in analog wristwatches. Also used in surgical instruments and as catalyst .

Sources

Obtained with platinum, nickel, copper and mercury ores.

Abundance
Abundance in Earth's crust
0.015 mg/kg
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor
0.000066 %
Abundance in Sun
0.0000003 %
Abundance in Universe
0.0000002 %

Nuclear Screening Constants

1s0.9411
2p4.07
2s12.1172
3d14.5489
3p16.9804
3s16.7788
4d32.3824
4p28.2768
4s27.014