Rh Rhodium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

Rhodium is a chemical element with symbol Rh and atomic number 45. It is a rare, silvery-white, hard, and chemically inert Transition Metal. It is a member of the platinum group.
It belongs to group 9 of the periodic table having trivial name .
Rhodium Facts
Read key information and facts about element Rhodium
Name | Rhodium |
Atomic Number | 45 |
Atomic Symbol | Rh |
Atomic Weight | 102.9055 |
Phase | Solid |
Color | Silver |
Appearance | silvery white metallic |
Classification | Transition Metal |
Group in Periodic Table | 9 |
Group Name | cobalt family |
Period in Periodic Table | period 5 |
Block in Periodic Table | d -block |
Electronic Configuration | [Kr] 4d8 5s1 |
Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 16, 1 |
Melting Point | 2237 K |
Boiling Point | 3968 K |
CAS Number | CAS7440-16-6 |
How to Locate Rhodium 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 45 to find Rhodium 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 Rhodium on periodic table look for cross section of group 9 and period 5 in the modern periodic table.
Rhodium History
The element Rhodium was discovered by H. Wollaston in year 1804 in United Kingdom. Rhodium was first isolated by H. Wollaston in 1804. Rhodium derived its name from the Greek rhodos, meaning 'rose coloured'.
Wollaston discovered and isolated it from crude platinum samples from South America.
Rhodium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Rhodium 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 | 0.6 | 0.007 |
Abundance in Sun | 2 | 0.02 |
Abundance in Meteorites | 180 | 40 |
Abundance in Earth's Crust | 0.70 | 0.1 |
Abundance in Oceans | - | - |
Abundance in Humans | - | - |
Crystal Structure of Rhodium
The solid state structure of Rhodium is Face 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 |
---|---|---|
380.34 pm | 380.34 pm | 380.34 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 | Fm_ 3m | ![]() |
Oxidation States | Space Group Number | 225 |
Crystal Structure | Face Centered Cubic |
Rhodium Atomic and Orbital Properties
Rhodium atoms have 45 electrons and the electronic shell structure is [2, 8, 18, 16, 1] with Atomic Term Symbol (Quantum Numbers) 4F9/2.
Atomic Number | 45 |
Number of Electrons (with no charge) | 45 |
Number of Protons | 45 |
Mass Number | 103 |
Number of Neutrons | 58 |
Shell structure (Electrons per energy level) | 2, 8, 18, 16, 1 |
Electron Configuration | [Kr] 4d8 5s1 |
Valence Electrons | 4d8 5s1 |
Valence (Valency) | 6 |
Main Oxidation States | 3 |
Oxidation States | -3, -1, 0, 1, 2, 3, 4, 5, 6 |
Atomic Term Symbol (Quantum Numbers) | 4F9/2 |
Bohr Atomic Model of Rhodium - Electrons per energy level

n | s | p | d | f |
---|
Ground State Electronic Configuration of Rhodium - neutral Rhodium atom
Abbreviated electronic configuration of Rhodium
The ground state abbreviated electronic configuration of Neutral Rhodium atom is [Kr] 4d8 5s1. The portion of Rhodium 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 4d8 5s1, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Rhodium
Complete ground state electronic configuration for the Rhodium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d8 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 Rhodium
Rhodium atomic radius is 173 pm, while it's covalent radius is 135 pm.
Atomic Radius Calculated | 173 pm (1.73 Å) |
Atomic Radius Empirical | 135 pm (1.35 Å) |
Atomic Volume | 8.2655 cm3/mol |
Covalent Radius | 135 pm (1.35 Å) |
Van der Waals Radius | - |
Neutron Cross Section | 145 |
Neutron Mass Absorption | 0.063 |
Atomic Spectrum of Rhodium
Rhodium Chemical Properties: Rhodium Ionization Energies and electron affinity
The electron affinity of Rhodium is 109.7 kJ/mol.
Valence | 6 |
Electronegativity | 2.28 |
ElectronAffinity | 109.7 kJ/mol |
Ionization Energy of Rhodium
Refer to table below for Ionization energies of Rhodium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 719.7 |
2nd | 1740 |
3rd | 2997 |
Rhodium Physical Properties
Refer to below table for Rhodium Physical Properties
Density | 12.45 g/cm3(when liquid at m.p density is $10.7 g/cm3) |
Molar Volume | 8.2655 cm3/mol |
Elastic Properties
Young Modulus | 275 |
Shear Modulus | 150 GPa |
Bulk Modulus | 380 GPa |
Poisson Ratio | 0.26 |
Hardness of Rhodium - Tests to Measure of Hardness of Element
Mohs Hardness | 6 MPa |
Vickers Hardness | 1246 MPa |
Brinell Hardness | 1100 MPa |
Rhodium Electrical Properties
Rhodium is Conductor of electricity. Refer to table below for the Electrical properties ofRhodium
Electrical Conductivity | 23000000 S/m |
Resistivity | 4.3e-8 m Ω |
Superconducting Point | - |
Rhodium Heat and Conduction Properties
Thermal Conductivity | 150 W/(m K) |
Thermal Expansion | 0.0000082 /K |
Rhodium Magnetic Properties
Magnetic Type | Paramagnetic |
Curie Point | - |
Mass Magnetic Susceptibility | 1.36e-8 m3/kg |
Molar Magnetic Susceptibility | 1.4e-9 m3/mol |
Volume Magnetic Susceptibility | 0.0001693 |
Optical Properties of Rhodium
Refractive Index | - |
Acoustic Properties of Rhodium
Speed of Sound | 4700 m/s |
Rhodium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Rhodium
Melting Point | 2237 K (1963.85°C, 3566.9299999999994 °F) |
Boiling Point | 3968 K (3694.85°C, 6682.7300000000005 °F) |
Critical Temperature | - |
Superconducting Point | - |
Enthalpies of Rhodium
Heat of Fusion | 21.7 kJ/mol |
Heat of Vaporization | 495 kJ/mol |
Heat of Combustion | - |
Rhodium Isotopes - Nuclear Properties of Rhodium
Rhodium has 27 isotopes, with between 89 and 115 nucleons. Rhodium has 1 stable naturally occuring isotopes.
Isotopes of Rhodium - Naturally occurring stable Isotopes: 103Rh.
Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|---|---|
89Rh | 45 | 44 | 89 | Synthetic | ||
90Rh | 45 | 45 | 90 | Synthetic | ||
91Rh | 45 | 46 | 91 | Synthetic | ||
92Rh | 45 | 47 | 92 | Synthetic | ||
93Rh | 45 | 48 | 93 | Synthetic | ||
94Rh | 45 | 49 | 94 | Synthetic | ||
95Rh | 45 | 50 | 95 | Synthetic | ||
96Rh | 45 | 51 | 96 | Synthetic | ||
97Rh | 45 | 52 | 97 | Synthetic | ||
98Rh | 45 | 53 | 98 | Synthetic | ||
99Rh | 45 | 54 | 99 | Synthetic | ||
100Rh | 45 | 55 | 100 | Synthetic | ||
101Rh | 45 | 56 | 101 | Synthetic | ||
102Rh | 45 | 57 | 102 | Synthetic | ||
103Rh | 45 | 58 | 103 | 100% | Stable | |
104Rh | 45 | 59 | 104 | Synthetic | ||
105Rh | 45 | 60 | 105 | Synthetic | ||
106Rh | 45 | 61 | 106 | Synthetic | ||
107Rh | 45 | 62 | 107 | Synthetic | ||
108Rh | 45 | 63 | 108 | Synthetic | ||
109Rh | 45 | 64 | 109 | Synthetic | ||
110Rh | 45 | 65 | 110 | Synthetic | ||
111Rh | 45 | 66 | 111 | Synthetic | ||
112Rh | 45 | 67 | 112 | Synthetic | ||
113Rh | 45 | 68 | 113 | Synthetic | ||
114Rh | 45 | 69 | 114 | Synthetic | ||
115Rh, 116Rh, 117Rh, 118Rh, 119Rh, 120Rh, 121Rh, 122Rh | 45 | 70 | 115 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
Database Search
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7440-16-6 |
RTECS Number | RTECSVI9069000 |
CID Number | CID23948 |
Gmelin Number | - |
NSC Number | - |
Compare Rhodium with other elements
Compare Rhodium with all Group 9 elements
Compare Rhodium with all Period 5 elements
Compare Rhodium with all Transition Metal elements
FAQs
What is the electronic configuration of Rhodium?
The electronic configuration of Rhodium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d8 5s1.
What is the abbreviated electronic configuration of Rhodium?
The abbreviated electronic configuration of Rhodium is [Kr] 4d8 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 Rhodium?
Symbol of Rhodium is Rh. Rhodium is a chemical element with symbol Rh and atomic number 45.
What is the position of Rhodium in the Periodic Table?
Rhodium is a chemical element with the symbol Rh and atomic number 45. Rhodium is the 45 element on the periodic table. It is located in group 9 and period 5 in the modern periodic table.
What is the atomic number of Rhodium?
The atomic number of Rhodium is 45.
What is the color of Rhodium?
Rhodium is of Silver color.
Who discovered Rhodium?
The element Rhodium was discovered by H. Wollaston in year 1804 in United Kingdom. Rhodium was first isolated by H. Wollaston in 1804.
How many valence electrons does a Rhodium atom have?
Rhodium has 6 valence electrons. Rhodium has 45 electrons out of which 6 valence electrons are present in the 4d8 5s1 outer orbitals of atom.
What is the melting Point of Rhodium?
Melting Point of Rhodium is 2237 K.
What is the boiling Point of Rhodium?
Boiling Point of Rhodium is 3968 K.
What is the melting Point of Rhodium in Kelvin?
Melting Point of Rhodium in Kelvin is 2237 K.
What is the boiling Point of Rhodium in Kelvin?
Boiling Point of Rhodium in Kelvin is 3968 K.
What is the electronic configuration of Rhodium 45?
The electronic configuration of Rhodium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d8 5s1.
How do you write the electron configuration for Rhodium?
The electronic configuration of Rhodium will be 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d8 5s1.