Element 46 · Palladium (Pd)

Palladium Bohr model: diagram and electrons per shell

The palladium Bohr model shows a palladium atom (Pd) as a small nucleus with its electrons circling it in 4 shells: 2 in shell K, 8 in shell L, 18 in shell M and 18 in shell N. This page has a rotating 3D palladium Bohr model, a flat diagram, a table of the electrons in each shell and the steps to draw it yourself.

Rotate the palladium Bohr model in 3D

Drag to orbit, scroll to zoom.

This is a Bohr model of palladium (Pd), a simplified picture of a single palladium atom. Its nucleus holds 46 protons, and a neutral palladium atom has 46 electrons, arranged around it in 4 shells (2 in shell K, 8 in shell L, 18 in shell M and 18 in shell N).

Pd K · 21s² L · 82s² 2p⁶ M · 183s² 3p⁶ 3d¹⁰ N · 184s² 4p⁶ 4d¹⁰

Palladium Bohr model diagram

Bohr model diagram of palladium: a nucleus of 46 protons with 46 electrons on 4 shells, 2 in shell K, 8 in shell L, 18 in shell M and 18 in shell N, each ring labelled with its shell letter. — The palladium 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 and 18 in shell N).

Palladium electrons per shell

A neutral palladium atom has 46 electrons, one for each of its 46 protons. They fill the shells from the nucleus outwards: 2 in shell K, 8 in shell L, 18 in shell M and 18 in shell N.

Electrons in each shell of the palladium 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	18	32	4s² 4p⁶ 4d¹⁰

How the palladium Bohr model builds up, shell by shell

Watch the palladium 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 and 18 in shell N) as it forms.

Animation of the palladium Bohr model being built: a nucleus of 46 protons appears first, then each shell grows in around it and takes its electrons, giving 46 electrons on 4 shells (2 in shell K, 8 in shell L, 18 in shell M and 18 in shell N). — The palladium 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 and 18 in shell N. Protons are red, neutrons yellow and electrons blue.

How to draw the palladium Bohr model

Find the atomic number. Palladium has atomic number 46, so a neutral atom has 46 protons and 46 electrons.
Draw the nucleus. Put a circle in the centre and write Pd in it. The 46 protons sit there with the neutrons.
Draw the shells. Sketch 4 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 and 18 in shell N.
Check the total. 2 + 8 + 18 + 18 = 46, the atomic number, so every electron is accounted for.

Atomic data for the palladium Bohr model

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

Identity

Symbol: Pd
Atomic number: 46
Atomic mass: 106.421 u
Family: Transition Metals
Position: group 10, period 5
Block: d-block

Electron configuration

Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 4d¹⁰
Shorthand: [Kr] 4d¹⁰
Electrons per shell: 2, 8, 18, 18
Outer-shell electrons: 18 in shell N

Ionisation energies

I₁: 804.4
I₂: 1870
I₃: 3177

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): 169
Empirical (pm): 140
Covalent (pm): 120
Van der Waals (pm): 163

Electronegativity and electron affinity

Electronegativity (Pauling): 2.2
Electron affinity (kJ/mol): 54.24

Oxidation states

+2 +4

Charges the element commonly takes in compounds.

Physical properties, abundance and history of palladium

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

Physical properties

Phase at room conditions: Solid
Appearance: Silvery white
Melting point: 1554.9°C (1828.05 K)
Boiling point: 2962.85°C (3236 K)
Density: 12.023 g/cm³
Thermal conductivity (W/m·K): 71.8
Specific heat (J/g·K): 0.246
Molar heat capacity (J/mol·K): 25.98
Heat of fusion (kJ/mol): 17.24
Heat of vaporisation (kJ/mol): 372.4

Abundance

Earth's crust (mg/kg): 0.015

Discovery

Discovered by: William Hyde Wollaston
Year: 1803

Common compounds

Palladium Chloride Cl2Pd
Palladium Pd
Dichloro(1,5-cyclooctadiene)palladium C8H12Cl2Pd
Diammonium hexachloropalladate Cl6H8N2Pd
palladium(II) acetate C4H6O4Pd
Tetrakis(triphenylphosphine)palladium C72H60P4Pd
Padeliporfin C37H43N5O9PdS
Palladium cyanide (Pd(CN)2) C2N2Pd

Compounds listed in the PubChem database.

Main isotopes of palladium

Isotopes of palladium share the same 46 protons but differ in neutrons. Natural isotopes come first, then the longest-lived others.

Main isotopes of palladium: mass number, abundance, half-life and decay
Mass number	Natural abundance	Half-life	Decay
102	1.02 %	stable	2β⁺
104	11.14 %	stable	–
105	22.33 %	stable	–
106	27.33 %	stable	–
108	26.46 %	stable	–
110	11.72 %	stable	2β⁻

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

More about palladium

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