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Pd

Palladium

Palladium (Pd) is a transition metal with atomic number 46 and an atomic mass of 106.42. Its electron configuration is [Kr] 4d10.

Palladium key data

Symbol Pd
Atomic number 46
Atomic mass (standard atomic weight) 106.42
Molar mass 106.42 g/mol
Protons 46
Neutrons (most abundant isotope, palladium-106) 60
Electrons (neutral atom) 46
Category Transition metal
Period 5
Group 10
Block d-block
Noble gas notation [Kr] 4d10
Full electron configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10
Electrons per shell 2, 8, 18, 18

Atomic mass: IUPAC CIAAW abridged standard atomic weights, 2024. Most abundant isotope: NIST Atomic Weights and Isotopic Compositions.

The values are facts and free to use; this page’s selection and presentation are © 2026 ScienceQuest.

Measured properties of palladium

From PubChem, the US National Institutes of Health. Public domain.

Melting point 1828.1 K (1554.9 °C), 23rd of 103 by melting point
Boiling point 3236 K (2962.9 °C), 34th of 93 by boiling point
Density 12 g/cm³, 19th of 96 by density
State at room temperature Solid
Electronegativity 2.2 (Pauling), joint 17th of 95 by electronegativity
Van der Waals radius 202 pm, joint 57th of 99 by atomic radius
First ionisation energy 8.337 eV (804.4 kJ/mol), 31st of 102 by first ionisation energy
Electron affinity 0.557 eV (53.7 kJ/mol), 35th of 57 by electron affinity
Common oxidation states +4, +2
Discovered 1803

Each rank counts down from the highest value, among the elements PubChem’s table gives one for, and links to that property ranked across the whole table. All of them are collected under periodic trends.

Palladium electron configuration

The full electron configuration of palladium is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10. With the noble-gas core collapsed it is [Kr] 4d10, and the outermost subshell is 4d10.

Palladium does not follow the simple filling order. Its measured configuration differs from the one the aufbau rule predicts, because a filled d subshell sits lower in energy than the arrangement the rule would give. This is a measured fact about the atom rather than an exception to be derived.

Bohr model of palladium (Pd): a nucleus and four shells holding 2, 8, 18 and 18 electrons from the inside out.
Bohr model of palladium (Pd). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.
Orbital box diagram of palladium (Pd), [Kr] 4d10, with the krypton core drawn as one bar: one box per orbital, filled by Hund’s rule, showing every orbital drawn holds a pair of electrons.
Orbital diagram of palladium (Pd). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Why group and block follow from this is set out in how the periodic table maps electron configuration, and the electron configuration of every element is listed on one page.

Mass of one palladium atom

A molar mass is grams per mole, so dividing by the Avogadro constant gives the mass of a single atom, or for an element with more than one natural isotope the average mass of its atoms, and the reciprocal gives how many atoms sit in a gram.

Mass of one atom

  1. one atom = 106.42 / (6.02214076 × 10²³)
  2. = 1.7671 × 10⁻²² g

Atoms in one gram

  1. atoms per gram = 6.02214076 × 10²³ / 106.42
  2. = 5.6588 × 10²¹ atoms

Palladium on the periodic table

Palladium is in period 5, group 10, in the d-block.

The other elements of group 10 are nickel, platinum and darmstadtium.

The rest of period 5

Work with palladium