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Palladium

What is Palladium

Palladium (pronunciation peh-LAY-dee-em [2]), represented by the chemical symbol or formula Pd [1], is a rare, lustrous element belonging to the family of transition metals [3]. Naturally occurring Pd is a mixture of 6 stable isotopes with mass numbers 102, 104, 105, 106, 108 and 110 [1, 3]. Besides that, it has 33 synthetic, radioactive isotopes with known half-lives [3]. Heating the metal with oxygen results in the formation of its oxide. It reacts with chlorine and fluorine when it is hot. It doesn’t react with most acids under normal conditions but does so when the acids are hot [4, 5].

Palladium Symbol

Where Is It Found

The metal can be found in its uncombined state in nature, in Brazil. Otherwise, it is mostly found in sulfide minerals like braggite [1].

History

Origin of Its Name: It is named after the asteroid Pallas that is in turn named after the Greek Goddess of wisdom of the same name [1].

Who Discovered Palladium: English chemist, William Hyde Wollaston [1, 2].

When Was It Discovered: Its discovery year is 1803 [1].

Palladium Metal

How Was It Discovered

Wollaston extracted the metal from platinum in 1803. He observed that when he added ordinary platinum to aqua regia (nitric acid+hydrochloric acid), not all of it dissolved. It left behind a residue from which he eventually isolated palladium. He kept his discovery a secret and sold it as a ‘new silver’. In February 1805, he announced himself as the discoverer and gave a full and convincing account of the new element and its properties [1].

Palladium Element

Palladium Identification
Atomic Number  46 [1]
CAS Number  7440-05-3 [1]
Position in the periodic table Group Period Block
  10 [1] 5 [1] d [1]

Location of Palladium in the Periodic Table

Properties and Characteristics of Palladium

General Properties
Atomic mass 106.42 atomic mass units [1]
Atomic weight 106.42 [1]
Mass number 106 [3]
Molar mass/molecular weight 106.42 g/mol [6]

Physical Properties
Color/appearance Silvery-white [3]
Melting point/freezing point 1554.8°C, 2830.6°F [1]
Boiling point 2963°C, 5365°F [1]
Density 12.0 g cm-3 [1]
State of matter at room temperature (normal phase) Solid [1]
Thermal Conductivity 71 W/(m K) [7]
Electrical Conductivity 1X107 S/m [7]
Specific gravity 12.02 [8]
Hardness (Mohs scale) 4.75 [9]

Chemical Properties
Oxidation state/Oxidation number (+1), +2, +4 [1]

Magnetic Properties
Magnetic ordering Paramagnetic [7]

Atomic Data of Palladium (Element 46)

Valence electrons 10 [12]
Valency +1, +2, +3, +4, +5, +6 [13]
Quantum numbers
– n 4 [10]
– ℓ 2 [10]
– m ℓ 2 [10]
– m s -½ [10]
Electron configuration (noble gas configuration) [Kr] 4d10 [1]
Crystal structure cubic close-packed [11]
Atomic structure
– Number of Electrons 46 [3]
– Number of Neutrons 60 [3]
– Number of Protons 46 [3]
Energy levels [3]
– First Energy Level 2
– Second Energy Level 8
– Third Energy Level 18
– Fourth Energy Level 18
Radius of atom
– Atomic Radius 2.10 Å [1]
– Covalent Radius 1.30 Å [1]
Electronegativity (Pauling scale) 2.20 [1]
Ionization energy

(kJmol-1) [1]

 1st 2nd 3rd 4th 5th 6th 7th 8th
804.389 1874.71 3177.26 – – – – –

Palladium Electron Configuration (Bohr Model)

Palladium Uses

  1. In catalytic converters of cars [1].
  2. In dental crowns and fillings.
  3. In jewelry. White gold used in ornaments is actually gold that has been made white by alloying it with palladium or another metal [1].
  4. It finds application in the electronics industry in making ceramic capacitors that form a part of laptops and mobile phones [1].
  5. Finely divided palladium being a good catalyst finds application in hydrogenation and dehydrogenation reactions [1].

Palladium Wedding Bands

Is It Dangerous

Palladium is a non-toxic element. It has no biological role [1].

Interesting Facts

  • Palladium doesn’t tarnish in air normally but does so slightly in moist air containing sulfur [3].
  • It can absorb up to 900 times its own volume of hydrogen. As it does so, it expands visibly just like a sponge swelling upon absorbing water [3].

Palladium

Palladium (Pd Element) Cost

The pure metal is priced at $5833 for every 100 gram and in bulk, the same quantity costs $1571 [3].

Palladium Ring

    References

  1. http://www.rsc.org/periodic-table/element/46/palladium
  2. https://education.jlab.org/itselemental/ele046.html
  3. https://www.chemicool.com/elements/palladium.html
  4. https://www.webelements.com/palladium/chemistry.html
  5. http://www.chemistryexplained.com/elements/L-P/Palladium.html
  6. https://www.convertunits.com/molarmass/Palladium
  7. http://periodictable.com/Elements/046/data.html
  8. https://www.palloys.com.au/technical/specific-gravities/
  9. https://www.prosumerdiamonds.com/platinum-vs-palladium/
  10. http://chemistry-reference.com/q_elements.asp?Symbol=Pd
  11. https://www.webelements.com/palladium/crystal_structure.html
  12. https://www.reference.com/science/many-valence-electrons-palladium-23cc62de4c83df50
  13. https://www.quora.com/How-is-the-valency-of-Palladium-determined-while-its-valence-electrons-is-18

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