Periodic Table Element Comparison: Compare Elements - Cesium vs Rubidium
Compare Cesium and Rubidium on the basis of their properties, attributes and periodic table facts. Compare elements on more than 90 properties. All the elements of similar categories show a lot of similarities and differences in their chemical, atomic, physical properties and uses. These similarities and dissimilarities should be known while we study periodic table elements. You can study the detailed comparison between Cesium vs Rubidium with most reliable information about their properties, attributes, facts, uses etc. You can compare Cs vs Rb on more than 90 properties like electronegativity , oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more. Cesium and Rubidium comparison table on more than 90 properties.
Cesium and Rubidium Comparison
Facts
| Name | Cesium | Rubidium |
|---|---|---|
| Atomic Number | 55 | 37 |
| Atomic Symbol | Cs | Rb |
| Atomic Weight | 132.90545 | 85.4678 |
| Phase at STP | Solid | Solid |
| Color | Silver | Silver |
| Metallic Classification | Alkali Metal | Alkali Metal |
| Group in Periodic Table | group 1 | group 1 |
| Group Name | lithium family | lithium family |
| Period in Periodic Table | period 6 | period 5 |
| Block in Periodic Table | s -block | s -block |
| Electronic Configuration | [Xe] 6s1 | [Kr] 5s1 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 18, 8, 1 | 2, 8, 18, 8, 1 |
| Melting Point | 301.59 K | 312.46 K |
| Boiling Point | 944 K | 961 K |
| CAS Number | CAS7440-46-2 | CAS7440-17-7 |
| Neighborhood Elements | Neighborhood Elements of Cesium | Neighborhood Elements of Rubidium |
History
| Parameter | Cesium | Rubidium |
|---|---|---|
| History | The element Cesium was discovered by R. Bunsen and R. Kirchhoff in year 1860 in Germany. Cesium derived its name from the Latin caesius, meaning 'sky blue'. | The element Rubidium was discovered by R. Bunsen and G. R. Kirchhoff in year 1861 in Germany. Rubidium derived its name from the Latin rubidus, meaning 'deep red'. |
| Discovery | R. Bunsen and R. Kirchhoff (1860) | R. Bunsen and G. R. Kirchhoff (1861) |
| Isolated | C. Setterberg (1882) | Hevesy () |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Cesium | Rubidium |
|---|---|---|
| Abundance in Universe | 0.8 / 0.01 | 10 / 0.1 |
| Abundance in Sun | 8 / 0.07 | 30 / 0.4 |
| Abundance in Meteorites | 140 / 20 | 3300 / 770 |
| Abundance in Earth's Crust | 1900 / 290 | 60000 / 14000 |
| Abundance in Oceans | 0.5 / 0.023 | 120 / 8.7 |
| Abundance in Humans | 20 / 1 | 4600 / 340 |
Crystal Structure and Atomic Structure
| Property | Cesium | Rubidium |
|---|---|---|
| Atomic Volume | 70.732 cm3/mol | 55.788 cm3/mol |
| Atomic Radius | 298 pm | 265 pm |
| Covalent Radius | 225 pm | 211 pm |
| Van der Waals Radius | 343 pm | 303 pm |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum | Not available |  |
| Lattice Constant | 614.1, 614.1, 614.1 pm | 558.5, 558.5, 558.5 pm |
| Lattice Angle | π/2, π/2, π/2 | π/2, π/2, π/2 |
| Space Group Name | Im_ 3m | Im_ 3m |
| Space Group Number | 229 | 229 |
| Crystal Structure | Body Centered Cubic  | Body Centered Cubic |
Atomic and Orbital Properties
| Property | Cesium | Rubidium |
|---|---|---|
| Atomic Number | 55 | 37 |
| Number of Electrons (with no charge) | 55 | 37 |
| Number of Protons | 55 | 37 |
| Mass Number | 132.90545 | 85.4678 |
| Number of Neutrons | 78 | 48 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 18, 8, 1 | 2, 8, 18, 8, 1 |
| Electron Configuration | [Xe] 6s1 | [Kr] 5s1 |
| Valence Electrons | 6s1 | 5s1 |
| Oxidation State | 1 | 1 |
| Atomic Term Symbol (Quantum Numbers) | 2S1/2 | 2S1/2 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Cesium has 1 stable naturally occuring isotopes while Rubidium has 1 stable naturally occuring isotopes.
| Parameter | Cesium | Rubidium |
|---|---|---|
| Known Isotopes | 112Cs, 113Cs, 114Cs, 115Cs, 116Cs, 117Cs, 118Cs, 119Cs, 120Cs, 121Cs, 122Cs, 123Cs, 124Cs, 125Cs, 126Cs, 127Cs, 128Cs, 129Cs, 130Cs, 131Cs, 132Cs, 133Cs, 134Cs, 135Cs, 136Cs, 137Cs, 138Cs, 139Cs, 140Cs, 141Cs, 142Cs, 143Cs, 144Cs, 145Cs, 146Cs, 147Cs, 148Cs, 149Cs, 150Cs, 151Cs | 71Rb, 72Rb, 73Rb, 74Rb, 75Rb, 76Rb, 77Rb, 78Rb, 79Rb, 80Rb, 81Rb, 82Rb, 83Rb, 84Rb, 85Rb, 86Rb, 87Rb, 88Rb, 89Rb, 90Rb, 91Rb, 92Rb, 93Rb, 94Rb, 95Rb, 96Rb, 97Rb, 98Rb, 99Rb, 100Rb, 101Rb, 102Rb |
| Stable Isotopes | Naturally occurring stable isotopes: 133Cs | Naturally occurring stable isotopes: 85Rb |
| Neutron Cross Section | 29 | 0.38 |
| Neutron Mass Absorption | 0.0077 | 0.0003 |
Chemical Properties: Ionization Energies and electron affinity
| Property | Cesium | Rubidium |
|---|---|---|
| Valence or Valency | 1 | 1 |
| Electronegativity | 0.79 Pauling Scale | 0.82 Pauling Scale |
| Electron Affinity | 45.5 kJ/mol | 46.9 kJ/mol |
| Ionization Energies | 1st: 375.7 kJ/mol 2nd: 2234.3 kJ/mol 3rd: 3400 kJ/mol | 1st: 403 kJ/mol 2nd: 2633 kJ/mol 3rd: 3860 kJ/mol 4th: 5080 kJ/mol 5th: 6850 kJ/mol 6th: 8140 kJ/mol 7th: 9570 kJ/mol 8th: 13120 kJ/mol 9th: 14500 kJ/mol 10th: 26740 kJ/mol |
Physical Properties
| Property | Cesium | Rubidium |
|---|---|---|
| Density | 1.879 g/cm3 | 1.532 g/cm3 |
| Molar Volume | 70.732 cm3/mol | 55.788 cm3/mol |
Elastic Properties | ||
| Young Modulus | 1.7 | 2.4 |
| Shear Modulus | - | - |
| Bulk Modulus | 1.6 GPa | 2.5 GPa |
| Poisson Ratio | - | - |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | 0.2 MPa | 0.3 MPa |
| Vickers Hardness | - | - |
| Brinell Hardness | 0.14 MPa | 0.216 MPa |
Electrical Properties | ||
| Electrical Conductivity | 5000000 S/m | 8300000 S/m |
| Resistivity | 2e-7 m Ω | 1.2e-7 m Ω |
| Superconducting Point | - | - |
Heat and Conduction Properties | ||
| Thermal Conductivity | 36 W/(m K) | 58 W/(m K) |
| Thermal Expansion | - | - |
Magnetic Properties | ||
| Magnetic Type | Paramagnetic | Paramagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | 2.8e-9 m3/kg | 2.6e-9 m3/kg |
| Molar Magnetic Susceptibility | 3.72e-10 m3/mol | 2.22e-10 m3/mol |
| Volume Magnetic Susceptibility | 0.00000526 | 0.00000398 |
Optical Properties | ||
| Refractive Index | - | - |
Acoustic Properties | ||
| Speed of Sound | - | 1300 m/s |
Thermal Properties - Enthalpies and thermodynamics
| Property | Cesium | Rubidium |
|---|---|---|
| Melting Point | 301.59 K | 312.46 K |
| Boiling Point | 944 K | 961 K |
| Critical Temperature | 1938 K | 2093 K |
| Superconducting Point | - | - |
Enthalpies | ||
| Heat of Fusion | 2.09 kJ/mol | 2.19 kJ/mol |
| Heat of Vaporization | 65 kJ/mol | 72 kJ/mol |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Cesium | Rubidium |
|---|---|---|
| CAS Number | CAS7440-46-2 | CAS7440-17-7 |
| RTECS Number | RTECSFK9225000 | RTECSVL8500000 |
| DOT Hazard Class | 4.3 | 4.3 |
| DOT Numbers | 1407 | 1423 |
| EU Number | - | - |
| NFPA Fire Rating | - | 3 |
| NFPA Health Rating | - | 2 |
| NFPA Reactivity Rating | - | - |
| NFPA Hazards | Water Reactive | Water Reactive |
| AutoIgnition Point | - | - |
| Flashpoint | - | - |
Compare With Other Elements
Compare Cesium and Rubidium with other elements of the periodic table.