See Also

Palladium

Palladium is a chemical element Chemical element

A chemical element, often called simply an element, is a substance [i] that can ... 

 with symbol Pd and atomic number 46. A rare silver-white transition metal Transition metal

In chemistry [i], the term transition metal has two possible meanings: ... 

 of the platinum group, palladium resembles platinum Platinum

Platinum is a chemical element [i] in the periodic table [i] that has the symbol Pt and atomic number [i] ... 

 chemically and is extracted from some copper Copper

Copper is a chemical element [i] in the periodic table [i] that has the symbol Cu and atomic number [i] ... 

 and nickel Nickel

Nickel is a metallic chemical element [i] in the periodic table [i] that has the symbol Ni and atomic number [i] ... 

 ores. It is primarily used as an industrial catalyst Catalyst

In chemistry, a catalyst is a substance [i] that decreases the activation energy [i] ... 

 and in jewelry Jewellery

Jewellery is literally any piece of fine material used to adorn oneself.... 

.

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Encyclopedia

Palladium is a chemical element Chemical element

A chemical element, often called simply an element, is a substance [i] that can... 

 with symbol Pd and atomic number 46. A rare silver-white transition metal Transition metal

In chemistry [i], the term transition metal has two possible meanings:
... 

 of the platinum group, palladium resembles platinum Platinum

Platinum is a chemical element [i] in the periodic table [i] that has the symbol Pt and atomic number [i] ... 

 chemically and is extracted from some copper Copper

Copper is a chemical element [i] in the periodic table [i] that has the symbol Cu and atomic number [i]... 

 and nickel Nickel

Nickel is a metallic chemical element [i] in the periodic table [i] that has the symbol Ni and atomic number [i] ... 

 ores. It is primarily used as an industrial catalyst Catalyst

In chemistry, a catalyst is a substance [i] that decreases the activation energy [i] ... 

 and in jewelry Jewellery

Jewellery is literally any piece of fine material used to adorn oneself.... 

.

Notable characteristics


Palladium is a soft silver-white metal that resembles platinum Platinum

Platinum is a chemical element [i] in the periodic table [i] that has the symbol Pt and atomic number [i] ... 

. It is the least dense and has the lowest melting point of the platinum group metals. It is soft and ductile when annealed and greatly increases its strength and hardness when it is cold-worked. Palladium is chemically attacked by sulfuric Sulfuric acid

Sulfuric acid , H [i]2S [i]O [i]4, is a strong mineral acid [i]. ... 

, nitric acid Nitric acid

The chemical compound [i] nitric acid , otherwise known as aqua fortis or spirit of nitre, i ... 

 and hydrochloric acid Hydrochloric acid

The chemical compound [i] hydrochloric acid is the aqueous [i] solution [i] of hydrogen chloride [i] g ... 

 in which it dissolves slowly. This metal also does not react with oxygen Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8.... 

 at normal temperatures . Palladium heated to 800°C produce layer of palladium-oxide . It lightly tarnishes in moist atmosphere containing sulfur.

This metal has the uncommon ability to absorb up to 900 times its own volume of hydrogen Hydrogen

|-
| Triple point [i] || 13.8033 K, 7.042 kPa
... 

 at room temperatures. It is thought that this possibly forms palladium hydride  but it is not yet clear if this is a true chemical compound.

When palladium has absorbed large amounts of hydrogen, it can swell up, like a sponge full of water, visible to the naked eye.

Common oxidation state Oxidation state

In chemistry [i], the oxidation state is a measure of the degree of oxidation [i] of an atom [i] in a chemical compound [i] ... 

s of palladium are 0,+1, +2 and +4. Although originally +3 was thought of as one of the fundamental oxidation states of palladium, there is no evidence for palladium occurring in the +3 oxidation state; this has been investigated via X-ray diffraction X-ray crystallography

X-ray crystallography is a technique in crystallography [i] in which the pattern produced by the diffraction [i] ... 

 for a number of compounds, indicating a dimer Dimer

... 

 of palladium and palladium instead. Recently, compounds with an oxidation state of +6 were synthesised.

Applications

When it is finely divided, palladium forms a good catalyst Catalyst

In chemistry, a catalyst is a substance [i] that decreases the activation energy [i] ... 

 and is used to speed up hydrogenation and dehydrogenation reactions, as well as in petroleum Petroleum

Petroleum or crude oil is a black, dark brown or greenish liquid [i] found in porous rock formati ... 

 cracking. A large number of carbon-carbon bond forming reactions in organic chemistry Organic chemistry

Organic chemistry is a specific discipline within the subject of chemistry [i]. ... 

  are facilitated by catalysis with palladium compounds. It is also alloy Alloy

An alloy is a combination, either in solution [i] or compound [i], of two or more elements [i] ... 

ed and used in jewelry Jewellery

Jewellery is literally any piece of fine material used to adorn oneself.... 

. Other uses;
  • The largest use of palladium today is in catalytic converters Catalytic converter

    A catalytic converter is a device used to reduce the toxicity of emissions from an internal combustion engine [i] ... 

    . Much research is in progress to discover ways to replace the much more expensive platinum Platinum

    Platinum is a chemical element [i] in the periodic table [i] that has the symbol Pt and atomic number [i] ... 

     with palladium in this application.
  • Palladium is one of the two metals which can be alloyed with gold Gold

    Gold is a highly sought-after precious metal [i] that for many centuries has been used as money [i], a store of value [i] ... 

     to produce White gold.
  • Similar to gold, palladium can be beaten into a thin leaf form as thin as 100 nm .
  • Since 1939 palladium itself has occasionally been used as a precious metal in jewelry Jewellery

    Jewellery is literally any piece of fine material used to adorn oneself.... 

    , often as a replacement for platinum Platinum

    Platinum is a chemical element [i] in the periodic table [i] that has the symbol Pt and atomic number [i] ... 

    . .
  • Hydrogen easily diffuses through heated palladium; thus, it provides a means of purifying the gas. Also, hydrogen Hydrogen

    |-

| Triple point [i] || 13.8033 K, 7.042 kPa
... 

 dissolved in palladium is highly reactive, allowing it to be used in various chemical reductions Redox

Redox reactions include all chemical processes [i] in which atoms have their oxidation number [i] ... 

.
  • Palladium are used as electrodes in multi-layer ceramic capacitors Capacitor

    A capacitor is an electric [i]al device that can store energy [i] in the electric field [i] between a pair of ... 

    .
  • Palladium is used in connector platings in consumer electronics.
  • Palladium is also used in dentistry Dentistry

    Dentistry is the art and science of prevention, diagnosis, and treatment of conditions, diseases, and di... 

    , watch Watch

    A watch is a small portable timepiece [i] or clock [i] that displays the time [i] and sometimes the day [i] ... 

     making, in aircraft spark plug Spark plug

    A spark plug is an electrical device that fits into the cylinder head [i] of some internal combustion engine [i] ... 

    s and in the production of surgical instruments and electrical contact Contact

    Contact means to touch physically or to communicate with.

... 

s.
  • Palladium is also used to make professional transverse flutes.
  • It is also used as Palladium-Hydrogen electrode in electrochemical studies.
  • Palladium dichloride Palladium(II) chloride

    Palladium(II) chloride, also known as palladium dichloride, is the chemical compound [i] with the ... 

     can absorb large amounts of carbon monoxide Carbon monoxide

    Carbon monoxide, with the chemical formula CO, is a colourless, odourless, and tasteless gas [i]. ... 

     gas, and is used in carbon monoxide detectors.

History

Palladium was discovered by William Hyde Wollaston William Hyde Wollaston

William Hyde Wollaston FRS [i] was an English [i] chemist [i] and physicist who is ... 

 in 1803. This element was named by Wollaston in 1804 after the asteroid Pallas 2 Pallas

2 Pallas ' was the second asteroid discovered, following 1 Ceres [i]. ... 

, which was discovered two years earlier.

Wollaston found element 46 in crude platinum ore from South America South America

South America is a continent [i] situated in the western hemisphere [i] and, mostly, ... 

. He did this by dissolving the ore in aqua regia Aqua regia

Aqua regia is a highly corrosive, fuming yellow or red solution formed by a fresh mixture of concentrat... 

, neutralizing the solution with sodium hydroxide Sodium hydroxide

Sodium hydroxide , also known as lye or caustic soda, is a caustic [i] metallic base [i] ... 

, Na Sodium

Sodium is a chemical element [i] which has the symbol Na , atomic number 11, atomic mass 22.9898 g/mol, oxidation number [i] ... 

OH, precipitating platinum as ammonium chloroplatinate through treatment with ammonium chloride Ammonium chloride

Ammonium chloride or Sal Ammoniac is, in its pure form, a clear white water-soluble crystalline salt [i] ... 

, N Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

H Hydrogen

|-
| Triple point [i] || 13.8033 K, 7.042 kPa
... 

4Cl, and then adding mercuric cyanide to form the compound palladium cyanide. Finally, he heated the resulting compound in order to extract palladium metal.

The compound palladium chloride Palladium(II) chloride

Palladium(II) chloride, also known as palladium dichloride, is the chemical compound [i] with the ... 

 was at one time prescribed as a tuberculosis Tuberculosis

Tuberculosis is an infectious disease [i] caused by the bacterium [i] Mycobacterium tuberculosis [i]'... 

 treatment at the rate of 0.065g per day . This treatment did not have many negative side effects, but was later replaced by more effective drugs.

The element played an essential role in the Fleischmann-Pons experiment Cold fusion

By definition, Cold fusion is a nuclear fusion [i] reaction that takes place at or near room temperature [i] ... 

, also known as cold fusion Cold fusion

By definition, Cold fusion is a nuclear fusion [i] reaction that takes place at or near room temperature [i] ... 

.

In 2000, Ford Motor Company Ford Motor Company

Ford Motor Company is an American [i] multinational corporation [i] and one of the largest ... 

 created a price bubble Economic bubble

* The South Sea Company [i]
  • Mississippi Company [i]

... 

 in palladium by stockpiling large amounts of the metal, fearing interrupted supplies from Russia Russia

Russia , also the Russian Federation , is a country [i] that stretches over a vast expanse of Eurasia [i] ... 

. As prices fell in early 2001, Ford lost nearly $1 billion U.S. dollars United States dollar

For details of current paper money [i] and coins, see Federal Reserve Note [i] and United States coinage [i] ... 

.

Occurrence

Palladium is found as a free metal and alloyed with platinum and gold with platinum group metals in placer Placer mining

Placer mining refers to the mining of alluvial deposits for mineral [i]s. ... 

 deposits of the Ural Mountains Ural Mountains

The Ural Mountains also known simply as the Urals and as the Riphean Mountains in Greco-Roman antiquity [i] ... 

, Australia Australia

Australia, officially the Commonwealth of Australia, is a country in the Southern Hemisphere [i] c ... 

, Ethiopia Ethiopia

Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a country situated in the Horn of Africa [i] ... 

, South South America

South America is a continent [i] situated in the western hemisphere [i] and, mostly, ... 

 and North America North America

North America is a continent [i] in the Earth [i]'s northern hemisphere [i] and almost fully in the western hemisphere [i]... 

. However it is commercially produced from nickel Nickel

Nickel is a metallic chemical element [i] in the periodic table [i] that has the symbol Ni and atomic number [i] ... 

-copper Copper

Copper is a chemical element [i] in the periodic table [i] that has the symbol Cu and atomic number [i]... 

 deposits found in South Africa South Africa

The Republic of South Africa is a country located at the southern tip of the Africa [i]n continent [i]. ... 

 and Ontario Ontario

Ontario is the most populous and second-largest in area of Canada [i]'s ten provinces [i] ... 

; the huge volume of ore processed makes this extraction profitable in spite of the low proportion of palladium in these ores.

About the possibility of producing palladium in reactors or extracting it from spent nuclear fuel, see Synthesis of noble metals.

See also .

Isotopes

Naturally-occurring palladium is composed of six isotopes. The most stable radioisotope Radionuclide

Atoms of chemical elements may have many isotopes with the same atomic numbers but different atomic weights /... 

s are 107Pd with a half-life of 6.5 million years, 103Pd with a half-life of 17 days, and 100Pd with a half-life of 3.63 days. Eighteen other radioisotopes have been characterized with atomic weights ranging from 92.936 u  to 119.924 u . Most of these have half-lifes that are less than a half an hour except 101Pd , 109Pd , and 112Pd .

The primary decay mode Radioactive decay

Radioactive decay is the set of various processes by which unstable atomic nuclei [i] ... 

 before the most abundant stable isotope, 106Pd, is electron capture and the primary mode after is beta decay Beta decay

In nuclear physics [i], beta decay is a type of radioactive [i] decay in which a beta particle [i] is e ... 

. The primary decay product before 106Pd is rhodium Rhodium

Rh [i] redirects here. For other uses, see rh [i]
... 

 and the primary product after is silver Silver

Silver is a chemical element [i] with the symbol Ag . ... 

.

Radiogenic 107Ag is a decay product of 107Pd and was first discovered in the Santa Clara, California Santa Clara, California

Santa Clara , founded in 1777 [i] and incorporated in 1852 [i], is a city in Santa Clara County [i] ... 

 meteorite of 1978. The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic Nucleosynthesis

Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons .... 

 event. 107Pd versus Ag correlations observed in bodies, which have clearly been melted since accretion of the solar system Solar System

The Solar System or solar system is the stellar system [i] comprising the Sun [i] and ... 

, must reflect the presence of short-lived nuclides in the early solar system.

References



See also

  • Palladium coin
  • Precious metal Precious metal

    A precious metal is a rare metallic [i] chemical element [i] of high economic [i] value.

... 


External links

  • - Online Encyclopedia