Element 45 · Rhodium (Rh)

Rhodium Bohr model: diagram and electrons per shell

The rhodium Bohr model shows a rhodium atom (Rh) as a small nucleus with its electrons circling it in 5 shells: 2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O. This page has a rotating 3D rhodium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the rhodium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of rhodium (Rh), a simplified picture of a single rhodium atom. Its nucleus holds 45 protons, and a neutral rhodium atom has 45 electrons, arranged around it in 5 shells (2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O).

Rh K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 164s² 4p⁶ 4d⁸ O · 15s¹

Rhodium Bohr model diagram

Bohr model diagram of rhodium: a nucleus of 45 protons with 45 electrons on 5 shells, 2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O, each ring labelled with its shell letter. — The rhodium Bohr model drawn flat: each ring is a shell, labelled with its letter, and every dot is an electron (2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O).

Rhodium electrons per shell

A neutral rhodium atom has 45 electrons, one for each of its 45 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O.

Electrons in each shell of the rhodium Bohr model
Shell	Shell number (n)	Electrons	Most it can hold (2n²)	Subshells
K	1	2	2	1s²
L	2	8	8	2s² 2p⁶
M	3	18	18	3s² 3p⁶ 3d¹⁰
N	4	16	32	4s² 4p⁶ 4d⁸
O	5	1	50	5s¹

How the rhodium Bohr model builds up, shell by shell

Watch the rhodium Bohr model come together: the nucleus first, then each shell in turn, from the innermost outwards, with its electrons joining the ring. The legend names every shell and counts its electrons, so you can read off the arrangement (2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O) as it forms.

Animation of the rhodium Bohr model being built: a nucleus of 45 protons appears first, then each shell grows in around it and takes its electrons, giving 45 electrons on 5 shells (2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O). — The rhodium Bohr model built up in six seconds: the nucleus first, then each shell with its electrons, ending with 2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O. Protons are red, neutrons yellow and electrons blue.

How to draw the rhodium Bohr model

Find the atomic number. Rhodium has atomic number 45, so a neutral atom has 45 protons and 45 electrons.
Draw the nucleus. Put a circle in the centre and write Rh in it. The 45 protons sit there with the neutrons.
Draw the shells. Sketch 5 shells as rings around the nucleus. A shell holds at most 2n² electrons: 2 in the first, 8 in the second, 18 in the third and 32 in the fourth.
Place the electrons. Fill from the inside out: 2 in shell K, 8 in shell L, 18 in shell M, 16 in shell N and 1 in shell O.
Check the total. 2 + 8 + 18 + 16 + 1 = 45, the atomic number, so every electron is accounted for.

Atomic data for the rhodium Bohr model

The numbers behind the rhodium Bohr model, grouped by topic. Radii are in picometres (pm) and energies in kilojoules per mole (kJ/mol).

Identity

Symbol: Rh
Atomic number: 45
Atomic mass: 102.9055 u
Family: Transition Metals
Position: group 9, period 5
Block: d-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁸
Shorthand: [Kr] 4d⁸ 5s¹
Electrons per shell: 2, 8, 18, 16, 1
Outer-shell electrons: 1 in shell O

Ionisation energies

I₁: 719.7
I₂: 1740
I₃: 2997

Energy to remove each electron in turn (kJ/mol). A sharp jump means the next electron comes from an inner shell.

Atomic radii

Calculated (pm): 173
Empirical (pm): 135
Covalent (pm): 125

Electronegativity and electron affinity

Electronegativity (Pauling): 2.28
Electron affinity (kJ/mol): 110.27

Oxidation states

Charges the element commonly takes in compounds.

Physical properties, abundance and history of rhodium

Bulk properties of rhodium, how common it is, who discovered it and some of its compounds.

Physical properties

Phase at room conditions: Solid
Appearance: Silvery white metallic
Melting point: 1963.85°C (2237 K)
Boiling point: 3694.85°C (3968 K)
Density: 12.41 g/cm³
Thermal conductivity (W/m·K): 150
Specific heat (J/g·K): 0.243
Molar heat capacity (J/mol·K): 24.98
Heat of fusion (kJ/mol): 21.8
Heat of vaporisation (kJ/mol): 494

Abundance

Earth's crust (mg/kg): 0.001

Discovery

Discovered by: William Hyde Wollaston
Year: 1803

Common compounds

Rhodium Rh
Rhodium chloride Cl3Rh
Rhodium(III) nitrate N3O9Rh
Rhodium chloride trihydrate Cl3H6O3Rh
Rhodium oxide (RhO2) O2Rh
Rhodium, carbonyl(2,4-pentanedionato-kappaO2,kappaO4)(triphenylphosphine)-, (SP-4-2)- C24H22O3PRh-
Trichloro[1,1,1-tris(diphenylphosphinomethyl)ethane]rhodium(III) C41H39Cl3P3Rh
Rhodium iodide (RhI3) I3Rh

Compounds listed in the PubChem database.

Main isotopes of rhodium

Isotopes of rhodium share the same 45 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of rhodium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
99	–	16.1 d	β⁺
100	–	20.8 h	β⁺, EC, e⁺
101	–	4.07 y	EC
102	–	207 d	β⁺, β⁻
103	100 %	stable	–
105	–	35.341 h	β⁻

α = alpha decay, β⁻ = beta-minus, β⁺ = beta-plus, EC = electron capture, SF = spontaneous fission, p / n = proton / neutron emission.

More about rhodium

Rhodium on the periodic table – properties, isotopes, uses and the full rhodium page.
Transition Metals – all transition metal elements and their trends.
Bohr model of every element – the Bohr model of all 118 elements.