Cesium (Cs)
Cesium is the 55th element in the periodic table and has a symbol of Cs and atomic number of 55. It has an atomic weight of 132.90545 and a mass number of 133. Cesium has fifty-five protons and seventy-eight neutrons in its nucleus, and fifty-five electrons in six shells. It is located in group one, period six and block s of the periodic table. Soft silvery-white metallic element belonging to group 1 of the periodic table. One of the three metals which are liquid at room temperature. Cs-133 is the natural, and only stable, isotope. Fifteen other radioisotopes exist. Caesium reacts explosively with cold water, and ice at temperatures above 157K. Caesium hydroxide is the strongest base known. Caesium is the most electropositive, most alkaline and has the least ionization potential of all the elements. Known uses include the basis of atomic clocks, catalyst for the hydrogenation of some organic compounds, and in photoelectric cells. Caesium was discovered by Gustav Kirchoff and Robert Bunsen in Germany in 1860 spectroscopically. Its identification was based upon the bright blue lines in its spectrum. The name comes from the latin word caesius, which means sky blue. Caesium should be considered highly toxic. Some of the radioisotopes are even more toxic.
| Atomic Number | 55 |
|---|---|
| Atomic Weight | 132.90545196 |
| Mass Number | 133 |
| Group | 1 |
|---|---|
| Period | 6 |
| Block | s |
| Protons | 55 p+ |
|---|---|
| Neutrons | 78 n0 |
| Electrons | 55 e- |
Physical Properties
| Atomic Radius | 260 pm
|
|---|---|
| Molar Volume | 70 cm³/mol
|
| Covalent Radius | 232 pm
|
| Metallic Radius | 235 pm
|
| Ionic Radius | 167 pm
|
| Crystal Radius | 181 pm
|
| Van der Waals Radius |
343 pm
|
| Density | 1.873 g/cm³
|
Chemical Properties
| Energy | |
|---|---|
| Proton Affinity | |
| Electron Affinity | 0.471626 eV/particle
|
| Ionization Energy | 3.893905548 eV/particle
|
| Heat of Vaporization | 68.3 kJ/mol
|
| Heat of Fusion | 2.09 kJ/mol
|
| Heat of Formation | 76.5 kJ/mol
|
| Electrons | |
| Electron Shells | 2, 8, 18, 18, 8, 1 |
 | |
| Valence Electrons | 1 ⓘ |
 | |
| Electron Configuration | [Xe] 6s1ⓘ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 |
  | |
| Oxidation States | -1, 1 |
| Electronegativity |
0.79
|
| Electrophilicity Index | 0.696095447101947 eV/particle
|
| States of Matter | |
| Phase | Solid |
| Gas Phase | |
| Boiling Point | 944.15 K
|
| Melting Point | 301.65 K
|
| Critical Pressure | 9.4 MPa
|
| Critical Temperature | 1,938.15 K
|
| Triple Point | |
| Visual | |
Cesium is a Silver. Cs has a CPK of #ff1493, Jmol of #57178f, and MOLCAS GV of #57178f. The Appearance of Element 55 is silvery gold. | |
| Color | Silver
|
| Appearance | silvery gold |
| Refractive Index | |
| Thermodynamic Properties | |
| Thermal Conductivity | 35.9 W/(m K)
|
| Thermal Expansion | |
| Molar Heat Capacity | 32.21 J/(mol K)
|
| Specific Heat Capacity | 0.242 J/(g⋅K)
|
| Heat Capacity Ratio (Adiabatic Index) | |
| Electrical Properties | |
| Type | Conductor |
| Electrical Conductivity | 5 MS/m
|
| Electrical Resistivity | 0.0000002 m Ω
|
| Superconducting Point | |
| Magnetism | |
| Type | paramagnetic |
| Magnetic Susceptibility (Mass) | 0.0000000028 m³/Kg
|
| Magnetic Susceptibility (Molar) | 0.000000000372 m³/mol
|
| Magnetic Susceptibility (Volume) | 0.00000526
|
| Magnetic Ordering | |
| Curie Point | |
| Neel Point | |
| Structure | |
The Crystal Structure of Cesium is BCC. The lattice constant of Cs is 6.05 Å. The lattice angles of Element 55 are π/2, π/2, π/2. | |
| Crystal Structure | Body Centered Cubic (BCC) |
| Lattice Constant | 6.05 Å
|
| Lattice Angles | π/2, π/2, π/2 |
| Mechanical Properties | |
Cesium has a Brinell of 0.14 MPa, and Mohs hardness of 0.2 MPa. The Bulk Modulus of Cs is 1.6 GPa. The Young Modulus of Element 55 is 1.7 GPa. | |
| Hardness |
0.2 MPa
|
| Bulk Modulus | 1.6 GPa
|
| Shear Modulus | |
| Young's Modulus | 1.7 GPa
|
| Poisson Ratio | |
| Speed of Sound | |
| Classification | |
The CAS Group of Cesium is IA. The IUPAC Group of Cs is IA. The Glawe Number of Element 55 is 8. The Mendeleev Number of Cesium (Cs) is 5. The Pettifor Number of Cesium is 8. The Geochemical Class of Cs is alkali metal. The Goldschmidt Class of Element 55 is litophile. | |
| Category | Alkali metals, Alkali metals |
| CAS Group | IA |
| IUPAC Group | IA |
| Glawe Number | 8 |
| Mendeleev Number | 5 |
| Pettifor Number | 8 |
| Geochemical Class | alkali metal |
| Goldschmidt Class | litophile |
Other
The Dipole Polarizability of Cesium is 400.9 plus or minus 0.7 a₀. Cs has a C6 Dispersion Coefficient (GB) of 6660 a₀. The Allotropes of Element 55 is . The Neutron Cross Section of Cesium (Cs) is 29. The Neutron Mass Absorption of Cesium is 0.0077. The Quantum Numbers of Cs is 2S1/2. The Space Group of Element 55 is 229 (Im_3m).
| Gas Basicity | |
|---|---|
| Dipole Polarizability | |
| C6 Dispersion Coefficient | |
| Allotropes | |
| Neutron Cross Section | 29
|
| Neutron Mass Absorption | 0.0077
|
| Quantum Numbers | 2S1/2 |
| Space Group | 229 (Im_3m) |
Isotopes of Cesium
| Stable Isotopes | 1 |
|---|---|
| Unstable Isotopes | 41 |
| Natural Isotopes | 1 |
111Cs
| Mass Number | 111 |
|---|---|
| Neutron Number | 56 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | |
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| p (proton emission) |
112Cs
| Mass Number | 112 |
|---|---|
| Neutron Number | 57 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 490 ± 30 us
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1994 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| p (proton emission) | 100% |
| α (α emission) | 0.26% |
113Cs
| Mass Number | 113 |
|---|---|
| Neutron Number | 58 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 16.94 ± 0.09 us
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1984 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| p (proton emission) | 100% |
114Cs
| Mass Number | 114 |
|---|---|
| Neutron Number | 59 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 570 ± 20 ms
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1978 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| α (α emission) | 0.018% |
| β+ p (β+-delayed proton emission) | 8.7% |
| β+α (β+-delayed α emission) | 0.19% |
115Cs
| Mass Number | 115 |
|---|---|
| Neutron Number | 60 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.4 ± 0.8 s
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1978 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| β+ p (β+-delayed proton emission) | 0.07% |
116Cs
| Mass Number | 116 |
|---|---|
| Neutron Number | 61 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 700 ± 40 ms
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1975 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| β+ p (β+-delayed proton emission) | 0.28% |
| β+α (β+-delayed α emission) | 0.049% |
117Cs
| Mass Number | 117 |
|---|---|
| Neutron Number | 62 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 8.4 ± 0.6 s
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1972 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
118Cs
| Mass Number | 118 |
|---|---|
| Neutron Number | 63 |
| Relative Atomic Mass | |
| G-Factor | 1.935 ± 0.0025
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 14 ± 2 s
|
| Spin | 2 |
| Quadrupole Moment | 1.31 ± 0.17
|
| Discovery Year | 1969 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| β+ p (β+-delayed proton emission) | 0.021% |
| β+α (β+-delayed α emission) | 0.0012% |
119Cs
| Mass Number | 119 |
|---|---|
| Neutron Number | 64 |
| Relative Atomic Mass | |
| G-Factor | 1.2111111111111 ± 0.0066666666666667
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 43 ± 0.2 s
|
| Spin | 9/2 |
| Quadrupole Moment | 2.65 ± 0.17
|
| Discovery Year | 1969 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| β+α (β+-delayed α emission) | 2% |
120Cs
| Mass Number | 120 |
|---|---|
| Neutron Number | 65 |
| Relative Atomic Mass | |
| G-Factor | 1.93 ± 0.01
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 60.4 ± 0.6 s
|
| Spin | 2 |
| Quadrupole Moment | 1.36 ± 0.07
|
| Discovery Year | 1969 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| β+α (β+-delayed α emission) | 2% |
| β+ p (β+-delayed proton emission) | 7% |
121Cs
| Mass Number | 121 |
|---|---|
| Neutron Number | 66 |
| Relative Atomic Mass | |
| G-Factor | 0.51266666666667 ± 0.0026666666666667
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 155 ± 4 s
|
| Spin | 3/2 |
| Quadrupole Moment | 0.79 ± 0.04
|
| Discovery Year | 1969 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
122Cs
| Mass Number | 122 |
|---|---|
| Neutron Number | 67 |
| Relative Atomic Mass | |
| G-Factor | 0.133 ± 0.002
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 21.18 ± 0.19 s
|
| Spin | 1 |
| Quadrupole Moment | -0.179 ± 0.01
|
| Discovery Year | 1969 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
| β+α (β+-delayed α emission) | 2% |
123Cs
| Mass Number | 123 |
|---|---|
| Neutron Number | 68 |
| Relative Atomic Mass | |
| G-Factor | 2.75 ± 0.014
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 5.88 ± 0.03 m
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1954 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
124Cs
| Mass Number | 124 |
|---|---|
| Neutron Number | 69 |
| Relative Atomic Mass | |
| G-Factor | 0.672 ± 0.003
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 30.9 ± 0.4 s
|
| Spin | 1 |
| Quadrupole Moment | -0.69 ± 0.04
|
| Discovery Year | 1969 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
125Cs
| Mass Number | 125 |
|---|---|
| Neutron Number | 70 |
| Relative Atomic Mass | |
| G-Factor | 2.814 ± 0.014
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 44.35 ± 0.29 m
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1954 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
126Cs
| Mass Number | 126 |
|---|---|
| Neutron Number | 71 |
| Relative Atomic Mass | |
| G-Factor | 0.776 ± 0.004
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.64 ± 0.02 m
|
| Spin | 1 |
| Quadrupole Moment | -0.64 ± 0.03
|
| Discovery Year | 1954 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
127Cs
| Mass Number | 127 |
|---|---|
| Neutron Number | 72 |
| Relative Atomic Mass | |
| G-Factor | 2.914 ± 0.014
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 6.25 ± 0.1 h
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1950 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
128Cs
| Mass Number | 128 |
|---|---|
| Neutron Number | 73 |
| Relative Atomic Mass | |
| G-Factor | 0.972 ± 0.005
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 3.64 ± 0.014 m
|
| Spin | 1 |
| Quadrupole Moment | -0.54 ± 0.03
|
| Discovery Year | 1951 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
129Cs
| Mass Number | 129 |
|---|---|
| Neutron Number | 74 |
| Relative Atomic Mass | |
| G-Factor | 2.978 ± 0.016
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 32.06 ± 0.06 h
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1950 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% |
130Cs
| Mass Number | 130 |
|---|---|
| Neutron Number | 75 |
| Relative Atomic Mass | |
| G-Factor | 1.458 ± 0.007
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 29.21 ± 0.04 m
|
| Spin | 1 |
| Quadrupole Moment | -0.056 ± 0.006
|
| Discovery Year | 1952 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 98.4% |
| β− (β− decay) | 1.6% |
131Cs
| Mass Number | 131 |
|---|---|
| Neutron Number | 76 |
| Relative Atomic Mass | |
| G-Factor | 1.4144 ± 0.0012
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 9.689 ± 0.016 d
|
| Spin | 5/2 |
| Quadrupole Moment | 0.59 ± 0.02
|
| Discovery Year | 1947 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| ϵ (electron capture) | 100% |
132Cs
| Mass Number | 132 |
|---|---|
| Neutron Number | 77 |
| Relative Atomic Mass | |
| G-Factor | 1.1095 ± 0.0035
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 6.48 ± 0.006 d
|
| Spin | 2 |
| Quadrupole Moment | 0.48 ± 0.02
|
| Discovery Year | 1953 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 98.13% |
| β− (β− decay) | 1.87% |
133Cs
| Mass Number | 133 |
|---|---|
| Neutron Number | 78 |
| Relative Atomic Mass | |
| G-Factor | 0.73651428571429 ± 0.0004
|
| Abundance | 100
|
| Radioactivity | Stable |
| Half Life | Not Radioactive ☢️ |
| Spin | 7/2 |
| Quadrupole Moment | -0.00343 ± 0.0001
|
| Discovery Year | 1921 |
| Parity | + |
134Cs
| Mass Number | 134 |
|---|---|
| Neutron Number | 79 |
| Relative Atomic Mass | |
| G-Factor | 0.747325 ± 0.00035
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 2.065 ± 0.0004 y
|
| Spin | 4 |
| Quadrupole Moment | 0.37 ± 0.02
|
| Discovery Year | 1940 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| ϵ (electron capture) | 0.0003% |
135Cs
| Mass Number | 135 |
|---|---|
| Neutron Number | 80 |
| Relative Atomic Mass | |
| G-Factor | 0.77951428571429 ± 0.00037142857142857
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.33 ± 0.19 My
|
| Spin | 7/2 |
| Quadrupole Moment | 0.048 ± 0.003
|
| Discovery Year | 1949 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
136Cs
| Mass Number | 136 |
|---|---|
| Neutron Number | 81 |
| Relative Atomic Mass | |
| G-Factor | 0.741 ± 0.003
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 13.01 ± 0.05 d
|
| Spin | 5 |
| Quadrupole Moment | 0.213 ± 0.015
|
| Discovery Year | 1951 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
137Cs
| Mass Number | 137 |
|---|---|
| Neutron Number | 82 |
| Relative Atomic Mass | |
| G-Factor | 0.81068571428571 ± 0.0004
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 30.04 ± 0.04 y
|
| Spin | 7/2 |
| Quadrupole Moment | 0.048 ± 0.002
|
| Discovery Year | 1951 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
138Cs
| Mass Number | 138 |
|---|---|
| Neutron Number | 83 |
| Relative Atomic Mass | |
| G-Factor | 0.233 ± 0.0013333333333333
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 33.5 ± 0.2 m
|
| Spin | 3 |
| Quadrupole Moment | 0.112 ± 0.017
|
| Discovery Year | 1943 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
139Cs
| Mass Number | 139 |
|---|---|
| Neutron Number | 84 |
| Relative Atomic Mass | |
| G-Factor | 0.768 ± 0.0011428571428571
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 9.27 ± 0.05 m
|
| Spin | 7/2 |
| Quadrupole Moment | -0.063 ± 0.014
|
| Discovery Year | 1939 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
140Cs
| Mass Number | 140 |
|---|---|
| Neutron Number | 85 |
| Relative Atomic Mass | |
| G-Factor | 0.134 ± 0.001
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 63.7 ± 0.3 s
|
| Spin | 1 |
| Quadrupole Moment | -0.094 ± 0.015
|
| Discovery Year | 1950 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
141Cs
| Mass Number | 141 |
|---|---|
| Neutron Number | 86 |
| Relative Atomic Mass | |
| G-Factor | 0.69457142857143 ± 0.0028571428571429
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 24.84 ± 0.16 s
|
| Spin | 7/2 |
| Quadrupole Moment | -0.42 ± 0.07
|
| Discovery Year | 1962 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 0.0342% |
142Cs
| Mass Number | 142 |
|---|---|
| Neutron Number | 87 |
| Relative Atomic Mass | |
| G-Factor | 0
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.687 ± 0.01 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1962 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 0.089% |
143Cs
| Mass Number | 143 |
|---|---|
| Neutron Number | 88 |
| Relative Atomic Mass | |
| G-Factor | 0.57933333333333 ± 0.0026666666666667
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.802 ± 0.008 s
|
| Spin | 3/2 |
| Quadrupole Moment | 0.44 ± 0.03
|
| Discovery Year | 1962 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 1.62% |
144Cs
| Mass Number | 144 |
|---|---|
| Neutron Number | 89 |
| Relative Atomic Mass | |
| G-Factor | -0.545 ± 0.003
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 994 ± 6 ms
|
| Spin | 1 |
| Quadrupole Moment | 0.29 ± 0.02
|
| Discovery Year | 1967 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 2.98% |
145Cs
| Mass Number | 145 |
|---|---|
| Neutron Number | 90 |
| Relative Atomic Mass | |
| G-Factor | 0.522 ± 0.0026666666666667
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 582 ± 4 ms
|
| Spin | 3/2 |
| Quadrupole Moment | 0.58 ± 0.06
|
| Discovery Year | 1971 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 12.8% |
146Cs
| Mass Number | 146 |
|---|---|
| Neutron Number | 91 |
| Relative Atomic Mass | |
| G-Factor | -0.514 ± 0.002
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 321.6 ± 0.9 ms
|
| Spin | 1 |
| Quadrupole Moment | 0.21 ± 0.03
|
| Discovery Year | 1971 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 14.2% |
| 2n (2-neutron emission) |
147Cs
| Mass Number | 147 |
|---|---|
| Neutron Number | 92 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 230.5 ± 0.9 ms
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1978 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 28.5% |
148Cs
| Mass Number | 148 |
|---|---|
| Neutron Number | 93 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 151.8 ± 1 ms
|
| Spin | 2 |
| Quadrupole Moment | |
| Discovery Year | 1978 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 28.7% |
| 2n (2-neutron emission) |
149Cs
| Mass Number | 149 |
|---|---|
| Neutron Number | 94 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 112.3 ± 2.5 ms
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1979 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 25% |
| 2n (2-neutron emission) |
150Cs
| Mass Number | 150 |
|---|---|
| Neutron Number | 95 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 81 ± 2.6 ms
|
| Spin | 2 |
| Quadrupole Moment | |
| Discovery Year | 1979 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | 44% |
| 2n (2-neutron emission) |
151Cs
| Mass Number | 151 |
|---|---|
| Neutron Number | 96 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 59 ± 19 ms
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1979 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) |
152Cs
| Mass Number | 152 |
|---|---|
| Neutron Number | 97 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | |
| Spin | |
| Quadrupole Moment | |
| Discovery Year | 1987 |
| Parity |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | |
| β− n (β−-delayed neutron emission) |
History
Robert Bunsen and Gustav Kirchhoff were the first to suggest finding cesium in 1860 by spectrum analysis. They discovered cesium by its two blue emission lines in a sample of Dürkheim mineral water. The pure metal was eventually isolated by the German chemist Carl Setterberg while working on his doctorate with Kekulé and Bunsen. From the Latin word caesius, sky blue
| Discoverers | Gustov Kirchoff, Robert Bunsen |
|---|---|
| Discovery Location | Germany |
| Discovery Year | 1860 |
| Etymology (Name Origin) | Latin: coesius (sky blue); for the blue lines of its spectrum. |
| Pronunciation | SEE-zi-em (English) |
Cesium compounds are considered to be mildly toxic
Cesium was the first element discovered using a spectroscope
Uses
The radioactive isotope cesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology. Cesium is also used in photoelectric cells and as a catalyst in the hydrogenation of organic compounds. Cesium vapor thermionic generators are low-power devices that convert heat energy to electrical energy. Used as a 'getter' to remove air traces in vacuum and cathode-ray tubes. Also used in producing photoelectric devices and atomic clocks. Since it ionizes readily, it is used as an ion rocket motor propellant.
Sources
Nuclear Screening Constants
| 1 | s | 1.0957 |
| 2 | p | 4.1804 |
| 2 | s | 14.4884 |
| 3 | d | 14.0194 |
| 3 | p | 18.4222 |
| 3 | s | 18.6226 |
| 4 | d | 32.1616 |
| 4 | p | 29.1424 |
| 4 | s | 27.9576 |
| 5 | p | 41.349 |
| 5 | s | 39.5555 |
| 6 | s | 48.637 |
Also Known As
- Cs
- element 55
- 55Cs
- cæsium
- cesium
Translations
- Norwegian Bokmålcesium
- Frenchcésium
- Italiancesio
- Russianцезий
- Norwegian Nynorskcesium
- Swedishcesium
- Danishcæsium
- GermanCaesium
- Hungariancézium
- Spanishcesio
- Afrikaanssesium
- Amharicሴሲየም
- AragoneseCesio
- Arabicسيزيوم
- AzerbaijaniSezium
- BelarusianЦэзій
- Bulgarianцезий
- Banglaসিজিয়াম
- BretonKeziom
- Bosniancezij
- Catalancesi
- CorsicanCesiu
- Czechcesium
- ChuvashЦези
- WelshCesiwm
- Greekκαίσιο
- Esperantocezio
- EstonianTseesium
- Basquezesio
- Persianسزیم
- Finnishcesium
- FriulianCesi
- IrishCaeisiam
- Galiciancesio
- ManxKaishum
- Hakka Chinesecaesium
- Hebrewצסיום
- Hindiसीज़ियम
- Fiji HindiCaesium
- CroatianCezij
- Haitian CreoleSezyòm
- Armenianցեզիում
- Interlinguacesium
- Indonesiansesium
- Idocesio
- Icelandicsesín
- Japaneseセシウム
- Lojbanblasodna
- Georgianცეზიუმი
- KazakhЦезий
- Kannadaಸೀಸಿಯಮ್
- Korean세슘
- KurdishSezyûm
- KomiЦезий
- Latincaesium
- LuxembourgishCäsium
- LigurianÇesio
- LithuanianCezis
- Latviancēzijs
- Macedonianцезиум
- Malayalamസീസിയം
- Marathiसिझियम
- Western MariЦезий
- MalaySesium
- Burmeseဆယ်ဆီယမ်
- Low GermanCäsium
- Dutchcesium
- OccitanCèsi
- Polishcez
- Western Panjabiسیزیم
- Portuguesecésio
- QuechuaSesyu
- Romaniancesiu
- YakutСезиум
- Siciliancesiu
- Serbo-CroatianCezijum
- Slovakcézium
- SlovenianCezij
- AlbanianCeziumi
- Serbianцезијум
- Saterland FrisianCesium
- SwahiliCaesi
- Tamilசீசியம்
- Teluguసీసియం
- Thaiซีเซียม
- TagalogSesyo
- TurkishSezyum
- Uyghurسېزىي
- Ukrainianцезій
- Urduسیزیئم
- VepsCezii
- Vietnamesexêsi
- WalloonCeziom
- WarayCesyo
- KalmykЦесиүм
- Yiddishצעז
- YorubaKesium
- Chinese铯
- JavaneseSesium
- Punjabiਸੀਜ਼ੀਅਮ
- CebuanoCesyo
- Central Kurdishسیزیۆم
- Odiaସିଜିଅମ
- Gujaratiસીસીયમ
- Scotscaesium
- Tatarцезий
- PiedmonteseCesio
- SomaliKaasiyaam
- Literary Chinese銫
- Cantonese銫
- Belarusian (Taraskievica orthography)цэз
- UzbekSeziy
- AromanianCesiu
- KyrgyzЦезий
- LimburgishCesium
- Malteseċesju
- LombardCesio
- Scottish GaelicCaesium
- Bhojpuriसीजियम
- Sanskritसेसियम
- Nepaliसिजियम
- Paliसेसियम
- Newariसेसियम
- Gan Chinese銫
- Mongolianцези
- cdoCaesium
- Min Nan ChineseCaesium
- FaroeseSesium
- Tibetanསྰེ་སིམ།
- AsturianCesiu
- BavarianZäsium
- Portuguese (Brazil)césio
- Tajikцезий
- Tatar (Cyrillic)цезий
- Wu Chinese铯
- kbpSɛzɩyɔm
- Lingua Franca Novasesio
- oloCezii
- Northern FrisianTseesium
- Chinese (Traditional)銫
- Chinese (Taiwan)銫
- Chinese (Simplified)铯
- SardinianTzèsiu
- English (United Kingdom)caesium
- BashkirЦезий
- Moroccan Arabicسيزيوم
- Egyptian Arabicسيزيوم
- Pashtoسېزيوم
- BikolSesyo
- CornishCesiom
- BalineseSésium
- English (United States)cesium
- GandaSeziyaamu
- Korean (North Korea)세시움
- ZuluUmCanga
