Rb Rubidium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Rubidium is a chemical element with symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metallic element of the Alkali Metal group, with an atomic mass of 85.4678. Elemental rubidium is highly reactive, with properties similar to those of other alkali metals, such as very rapid oxidation in air.
It belongs to group 1 of the periodic table having trivial name alkali metals*.
Rubidium Facts
Read key information and facts about element Rubidium
| Name | Rubidium |
| Atomic Number | 37 |
| Atomic Symbol | Rb |
| Atomic Weight | 85.4678 |
| Phase | Solid |
| Color | Silver |
| Appearance | grey white |
| Classification | Alkali Metal |
| Group in Periodic Table | 1 |
| Group Name | lithium family |
| Period in Periodic Table | period 5 |
| Block in Periodic Table | s -block |
| Electronic Configuration | [Kr] 5s1 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 8, 1 |
| Melting Point | 312.46 K |
| Boiling Point | 961 K |
| CAS Number | CAS7440-17-7 |
How to Locate Rubidium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 37 to find Rubidium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Rubidium on periodic table look for cross section of group 1 and period 5 in the modern periodic table.
Rubidium History
The element Rubidium was discovered by R. Bunsen and G. R. Kirchhoff in year 1861 in Germany. Rubidium was first isolated by Hevesy in . Rubidium derived its name from the Latin rubidus, meaning 'deep red'.
Bunsen and Kirchhoff discovered it just a few months after caesium, by observing new spectral lines in the minerallepidolite. Bunsen never obtained a pure sample of the metal, which was later obtained by Hevesy.
Rubidium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Rubidium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
| ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
|---|---|---|
| Abundance in Universe | 10 | 0.1 |
| Abundance in Sun | 30 | 0.4 |
| Abundance in Meteorites | 3300 | 770 |
| Abundance in Earth's Crust | 60000 | 14000 |
| Abundance in Oceans | 120 | 8.7 |
| Abundance in Humans | 4600 | 340 |
Crystal Structure of Rubidium
The solid state structure of Rubidium is Body Centered Cubic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
| a | b | c |
|---|---|---|
| 558.5 pm | 558.5 pm | 558.5 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| π/2 | π/2 | π/2 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
| Space Group Name | Im_ 3m |
| Space Group Number | 229 |
| Crystal Structure | Body Centered Cubic |
| Number of atoms per unit cell | 2 |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Rubidium Atomic and Orbital Properties
Rubidium atoms have 37 electrons and the electronic shell structure is [2, 8, 18, 8, 1] with Atomic Term Symbol (Quantum Numbers) 2S1/2.
| Atomic Number | 37 |
| Number of Electrons (with no charge) | 37 |
| Number of Protons | 37 |
| Mass Number | 85 |
| Number of Neutrons | 48 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 8, 1 |
| Electron Configuration | [Kr] 5s1 |
| Valence Electrons | 5s1 |
| Valence (Valency) | 1 |
| Main Oxidation States | 1 |
| Oxidation States | -1, 1 |
| Atomic Term Symbol (Quantum Numbers) | 2S1/2 |
Bohr Atomic Model of Rubidium - Electrons per energy level
| n | s | p | d | f |
|---|
Ground State Electronic Configuration of Rubidium - neutral Rubidium atom
Abbreviated electronic configuration of Rubidium
The ground state abbreviated electronic configuration of Neutral Rubidium atom is [Kr] 5s1. The portion of Rubidium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Kr]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 5s1, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Rubidium
Complete ground state electronic configuration for the Rubidium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Rubidium
Rubidium atomic radius is 265 pm, while it's covalent radius is 211 pm.
| Atomic Radius Calculated | 265 pm (2.65 Å) |
| Atomic Radius Empirical | 235 pm (2.35 Å) |
| Atomic Volume | 55.788 cm3/mol |
| Covalent Radius | 211 pm (2.11 Å) |
| Van der Waals Radius | 303 pm |
| Neutron Cross Section | 0.38 |
| Neutron Mass Absorption | 0.0003 |
Atomic Spectrum of Rubidium
Rubidium Chemical Properties: Rubidium Ionization Energies and electron affinity
The electron affinity of Rubidium is 46.9 kJ/mol.
| Valence | 1 |
| Electronegativity | 0.82 |
| ElectronAffinity | 46.9 kJ/mol |
Ionization Energy of Rubidium
Refer to table below for Ionization energies of Rubidium
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1st | 403 |
| 2nd | 2633 |
| 3rd | 3860 |
| 4th | 5080 |
| 5th | 6850 |
| 6th | 8140 |
| 7th | 9570 |
| 8th | 13120 |
| 9th | 14500 |
| 10th | 26740 |
Rubidium Physical Properties
Refer to below table for Rubidium Physical Properties
| Density | 1.532 g/cm3(when liquid at m.p density is $1.46 g/cm3) |
| Molar Volume | 55.788 cm3/mol |
Elastic Properties
| Young Modulus | 2.4 |
| Shear Modulus | - |
| Bulk Modulus | 2.5 GPa |
| Poisson Ratio | - |
Hardness of Rubidium - Tests to Measure of Hardness of Element
| Mohs Hardness | 0.3 MPa |
| Vickers Hardness | - |
| Brinell Hardness | 0.216 MPa |
Rubidium Electrical Properties
Rubidium is Conductor of electricity. Refer to table below for the Electrical properties ofRubidium
| Electrical Conductivity | 8300000 S/m |
| Resistivity | 1.2e-7 m Ω |
| Superconducting Point | - |
Rubidium Heat and Conduction Properties
| Thermal Conductivity | 58 W/(m K) |
| Thermal Expansion | - |
Rubidium Magnetic Properties
| Magnetic Type | Paramagnetic |
| Curie Point | - |
| Mass Magnetic Susceptibility | 2.6e-9 m3/kg |
| Molar Magnetic Susceptibility | 2.22e-10 m3/mol |
| Volume Magnetic Susceptibility | 0.00000398 |
Optical Properties of Rubidium
| Refractive Index | - |
Acoustic Properties of Rubidium
| Speed of Sound | 1300 m/s |
Rubidium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Rubidium
| Melting Point | 312.46 K (39.31°C, 102.75800000000001 °F) |
| Boiling Point | 961 K (687.85°C, 1270.13 °F) |
| Critical Temperature | 2093 K |
| Superconducting Point | - |
Enthalpies of Rubidium
| Heat of Fusion | 2.19 kJ/mol |
| Heat of Vaporization | 72 kJ/mol |
| Heat of Combustion | - |
Rubidium Isotopes - Nuclear Properties of Rubidium
Rubidium has 32 isotopes, with between 71 and 102 nucleons. Rubidium has 1 stable naturally occuring isotopes.
Isotopes of Rubidium - Naturally occurring stable Isotopes: 85Rb.
| Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|---|---|
| 71Rb | 37 | 34 | 71 | Synthetic | ||
| 72Rb | 37 | 35 | 72 | Synthetic | ||
| 73Rb | 37 | 36 | 73 | Synthetic | ||
| 74Rb | 37 | 37 | 74 | Synthetic | ||
| 75Rb | 37 | 38 | 75 | Synthetic | ||
| 76Rb | 37 | 39 | 76 | Synthetic | ||
| 77Rb | 37 | 40 | 77 | Synthetic | ||
| 78Rb | 37 | 41 | 78 | Synthetic | ||
| 79Rb | 37 | 42 | 79 | Synthetic | ||
| 80Rb | 37 | 43 | 80 | Synthetic | ||
| 81Rb | 37 | 44 | 81 | Synthetic | ||
| 82Rb | 37 | 45 | 82 | Synthetic | ||
| 83Rb | 37 | 46 | 83 | Synthetic | ||
| 84Rb | 37 | 47 | 84 | Synthetic | ||
| 85Rb | 37 | 48 | 85 | 72.17% | Stable | |
| 86Rb | 37 | 49 | 86 | Synthetic | ||
| 87Rb | 37 | 50 | 87 | 27.83% | Stable | N/A |
| 88Rb | 37 | 51 | 88 | Synthetic | ||
| 89Rb | 37 | 52 | 89 | Synthetic | ||
| 90Rb | 37 | 53 | 90 | Synthetic | ||
| 91Rb | 37 | 54 | 91 | Synthetic | ||
| 92Rb | 37 | 55 | 92 | Synthetic | ||
| 93Rb | 37 | 56 | 93 | Synthetic | ||
| 94Rb | 37 | 57 | 94 | Synthetic | ||
| 95Rb | 37 | 58 | 95 | Synthetic | ||
| 96Rb | 37 | 59 | 96 | Synthetic | ||
| 97Rb | 37 | 60 | 97 | Synthetic | ||
| 98Rb | 37 | 61 | 98 | Synthetic | ||
| 99Rb | 37 | 62 | 99 | Synthetic | ||
| 100Rb | 37 | 63 | 100 | Synthetic | ||
| 101Rb | 37 | 64 | 101 | Synthetic | ||
| 102Rb | 37 | 65 | 102 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
| DOT Hazard Class | 4.3 |
| DOT Numbers | 1423 |
| EU Number | - |
| NFPA Fire Rating | 3 |
| NFPA Hazards | Water Reactive |
| NFPA Health Rating | 2 |
| NFPA Reactivity Rating | - |
| Autoignition Point | - |
| Flashpoint | - |
Database Search
List of unique identifiers to search the element in various chemical registry databases
| Database | Identifier number |
|---|---|
| CAS Number - Chemical Abstracts Service (CAS) | CAS7440-17-7 |
| RTECS Number | RTECSVL8500000 |
| CID Number | CID5357696 |
| Gmelin Number | - |
| NSC Number | - |
Compare Rubidium with other elements
Compare Rubidium with all Group 1 elements
Compare Rubidium with all Period 5 elements
Compare Rubidium with all Alkali Metal elements
FAQs
What is the electronic configuration of Rubidium?
The electronic configuration of Rubidium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1.
What is the abbreviated electronic configuration of Rubidium?
The abbreviated electronic configuration of Rubidium is [Kr] 5s1. To form abbreviated notation of electronic configuration, the completely filled subshells are replaced by the noble gas of the preceding period in square brackets.
What is the symbol of Rubidium?
Symbol of Rubidium is Rb. Rubidium is a chemical element with symbol Rb and atomic number 37.
What is the position of Rubidium in the Periodic Table?
Rubidium is a chemical element with the symbol Rb and atomic number 37. Rubidium is the 37 element on the periodic table. It is located in group 1 and period 5 in the modern periodic table.
What is the atomic number of Rubidium?
The atomic number of Rubidium is 37.
What is the color of Rubidium?
Rubidium is of Silver color.
Who discovered Rubidium?
The element Rubidium was discovered by R. Bunsen and G. R. Kirchhoff in year 1861 in Germany. Rubidium was first isolated by Hevesy in undefined.
How many valence electrons does a Rubidium atom have?
Rubidium has 1 valence electrons. Rubidium has 37 electrons out of which 1 valence electrons are present in the 5s1 outer orbitals of atom.
What is the melting Point of Rubidium?
Melting Point of Rubidium is 312.46 K.
What is the boiling Point of Rubidium?
Boiling Point of Rubidium is 961 K.
What is the melting Point of Rubidium in Kelvin?
Melting Point of Rubidium in Kelvin is 312.46 K.
What is the boiling Point of Rubidium in Kelvin?
Boiling Point of Rubidium in Kelvin is 961 K.
What is the electronic configuration of Rubidium 37?
The electronic configuration of Rubidium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1.
How do you write the electron configuration for Rubidium?
The electronic configuration of Rubidium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s1.