{"id":310,"date":"2020-04-09T10:34:01","date_gmt":"2020-04-09T10:34:01","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=310"},"modified":"2023-08-15T12:53:57","modified_gmt":"2023-08-15T12:53:57","slug":"palladium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/palladium\/","title":{"rendered":"Palladium (Pd)"},"content":{"rendered":"\n

Palladium is a chemical element with the atomic number 46 in the periodic table. It\u2019s the most abundant platinum<\/a> metal and occurs in Earth\u2019s crust at an abundance of 0.015 parts per million. Being a member of the platinum group metals (PGM) of the periodic table, palladium has three valence electrons and adopts the oxidation states of +4, +2, and 0 when it becomes a part of a compound.\u00a0<\/span><\/p>\n\n\n\n

While palladium is considered to be relatively safe and non-toxic, its compounds are highly dangerous and may lead to serious health conditions. This precious metal is often used as a catalytic in the petrochemical and automotive industry.\u00a0<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Palladium<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
Symbol<\/td>Pd<\/td><\/tr>
Name<\/td>Palladium<\/td><\/tr>
Atomic number<\/td>46<\/td><\/tr>
Atomic weight (mass)<\/td>106.42 g.mol-1<\/td><\/tr>
Group number<\/td>10 (Transition Metal)<\/td><\/tr>
Period<\/td>5 (d-block)<\/td><\/tr>
Color<\/td>A lustrous silvery-white metal<\/td><\/tr>
Physical state<\/td>Solid at 20\u00b0C<\/td><\/tr>
Half-life<\/td>From 10 milliseconds [>1.5 milliseconds] to 6.5 million years<\/td><\/tr>
Electronegativity according to Pauling<\/td>2.2<\/td><\/tr>
Density<\/td>12.02 g.cm-3<\/td><\/tr>
Melting point<\/td>1554.8\u00b0C, 2830.6\u00b0F, 1828 K<\/td><\/tr>
Boiling point<\/td>2963\u00b0C, 5365\u00b0F, 3236 K<\/td><\/tr>
Van der Waals radius<\/td>0.065 nm (+2)<\/td><\/tr>
Ionic radius<\/td>0.64 nm (+2)<\/td><\/tr>
Most characteristic isotope<\/td>106Pd<\/td><\/tr>
Electronic shell<\/td>[Kr] 4d10<\/td><\/tr>
The energy of the first ionization<\/td>703 kJ.mol-1<\/td><\/tr>
The energy of the second ionization<\/td>1870 kJ.mol-1<\/td><\/tr>
The energy of the third ionization<\/td>3177 kJ.mol-1<\/td><\/tr>
Uses<\/td>Used as a substitute for silver in dental items and jewelry. The pure metal is used as the delicate mainsprings in analog wristwatches. Also used in surgical instruments and as a catalyst.<\/td><\/tr>
Description<\/td>Silvery-ductile, and malleable metal<\/td><\/tr>
Shells<\/td>2,8,18,18<\/td><\/tr>
Valence<\/td>2,3,4<\/td><\/tr>
Crystal Structure<\/td>Cubic: Face centered<\/td><\/tr>
Covalent Radius<\/td>1.28 \u00c5<\/td><\/tr>
Atomic Radius<\/td>1.79 \u00c5<\/td><\/tr>
Atomic Volume<\/td>08.9 cm\u00b3\/mol<\/td><\/tr>
Name Origin<\/td>Named after the asteroid, Pallas, discovered in 1803.<\/td><\/tr>
Discovery date<\/td>In 1803 by William Wollaston<\/td><\/tr>
Location<\/td>England<\/td><\/tr>
Pronunciation<\/td>peh-LAY-di-em<\/td><\/tr>
Oxidation States<\/td>(2),4<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

With the periodic table symbol Pd, atomic number 46, atomic mass of 106.42 g.mol-1, and electron configuration [Kr]4d10, palladium is a precious soft, ductile, and lustrous silvery-white metal with a face-centered cubic crystalline structure. Element 46 reaches its boiling point at 2963\u00b0C, 5365\u00b0F, 3236 K, while the melting point of palladium is achieved at 1554.8\u00b0C, 2830.6\u00b0F, 1828 K. This member of the platinum group metals in the periodic table has an electronegativity of 2.2 according to Pauling, whereas the atomic radius according to van der Waals is 0.065 nm (+2).\u00a0<\/span><\/p>\n\n\n\n

When exposed to air at room temperature, palladium is strongly resistant to corrosion. While element 46 is readily attacked by acid heated to high temperatures, it can be dissolved in aqua regia.\u00a0<\/span><\/p>\n\n\n\n

Palladium is soft and more ductile at higher temperatures, while lower temperatures make this element both harder and stronger. In addition, this chemical element does not tarnish when exposed to air, but it does lose the luster in moist environments that contain sulfur<\/a>.<\/span><\/p>\n\n\n\n

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How Was Palladium Discovered?<\/span><\/h2>\n\n\n\n

During the 1700s, the Brazilian miners were familiar with a <\/span>native alloy<\/span><\/a> of palladium and gold<\/a>, referred to as \u2018<\/span>ouro podre<\/span><\/i>\u2019, i.e. \u2018<\/span>worthless or rotten gold<\/span><\/i>\u2019. However, the palladium metal was not extracted until a century later.<\/span><\/p>\n\n\n\n

In 1803, the English chemist William Hyde Wollaston (1766-1828) focused his scientific analysis on the residues left from platinum after it had been dissolved in aqua regia. When he provoked the chemical reaction between the platinum residue and the solution of nitric acid and hydrochloric acid, Wollaston managed to produce palladium cyanide. In the final step of his experiment, the English chemist heated the palladium compound which resulted in the extraction of the pure palladium metal.\u00a0<\/span><\/p>\n\n\n\n

William Hyde Wollaston announced the discovery of the new chemical element in a highly unusual way. Namely, instead of submitting the scientific evidence to the higher instances of the scientific world, Wollaston offered some quantity of the newly discovered metal for sale, describing its properties to anyone who\u00a0 was interested in buying it and advertising it as \u201cthe new silver\u201d. Wollaston also offered a price to anyone who\u2019ll be able to reproduce the substance. As could be expected, nobody ever got the prize.\u00a0<\/span><\/p>\n\n\n\n

However, a few years later he did reveal himself as the discoverer of palladium in front of the Royal Society of London after he finished his presentation of the scientific findings and evidence. Later, Wollaston claimed that the reason for not coming immediately upfront with his discovery was his intention to confirm the findings on the new element again by himself before putting his name on the discovery and in front of the scientific world.\u00a0<\/span><\/p>\n\n\n\n

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How Did Palladium Get Its Name?<\/span><\/h2>\n\n\n\n

This chemical element is named after the asteroid Pallas, which is – in turn – named after the Greek goddess of wisdom, Pallas. The etymology of <\/span>palladium<\/span><\/i> leads to the Greek word \u2018<\/span>pallo<\/span><\/i>\u2019, meaning \u2018the one who brandishes a spear\u2019.<\/span><\/p>\n\n\n\n

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Where Can You Find Palladium?<\/span><\/h2>\n\n\n\n

The elemental form of palladium is rarely found in its pure form. However, this chemical element is one of the most abundant ones that occur in Earth\u2019s crust along other chemical elements. It mostly occurs in sulfide minerals such as braggite.<\/span><\/p>\n\n\n\n

For commercial purposes, palladium is often obtained as a by-product of the refining processes of copper<\/a> and nickel<\/a> ores. The majority of the world\u2019s palladium supplies come from the United States, Australia, Russia, South Africa, Ethiopia, Canada, Brazil, and Colombia. These countries are considered to be the world\u2019s leading producers of this precious metal.\u00a0<\/span><\/p>\n\n\n\n

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List of Palladium Minerals<\/span><\/h3>\n\n\n\n

The following is a list of palladium-rich minerals:<\/span><\/p>\n\n\n\n