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About Palladium

Palladium Bohr Model

Palladium is one of six platinum-group metals, discovered by William Hyde Wollaston in 1802 as he attempted to process platina deposits into workable platinum metal. He named the new element after the also freshly discovered asteroid Pallas, and he initially made the strange decision to offer it for sale anonymously through distribution of an advertisement in 1803 but later disclosed his discovery officially in a scientific publication.

Palladium is similar to other platinum group elements in that it is a silvery metal that is relatively non-reactive, but of the group it has the lowest melting point and is the least dense. In its applications it is most similar to platinum: useful in metallic form for the production of a variety of products and as a catalyst. Palladium catalyzes reactions involved in petroleum cracking, water treatment, nitric acid production, and polymer manufacturing, and is found in catalytic converters and fuel cells as a catalyst. Additionally, palladium is used to increase the rate of hydrogenation and dehydrogenation reactions, and serves many specialized catalytic functions in organic chemistry. In fact, the 2010 Nobel Prize in Chemistry was given for the development of palladium-catalysed reactions used in organic synthesis. As a metal, palladium is used in in electronics for plating of components, electrical contacts, and solder, and is also found in jewelry, watches, blood sugar test strips, and surgical instruments. Alloyed with silver, palladium is used as electrodes in the production of multilayer ceramic capacitors. Finally, a niche use of both platinum and palladium salts is in the production of fine-art black and white photographic prints with the platinotype process.

Some other uses of palladium rely on chemistry unshared with platinum. Several of these involve useful interactions platinum has with hydrogen. As a gas, hydrogen easily diffuses through heated palladium, and thus palladium is used in the production of high purity hydrogen. Palladium also absorbs hydrogen gas, forming palladium hydride. This property is being researched for insights regarding hydrogen storage. Palladium chloride efficiently oxidizes carbon monoxide, and is used in detectors for the toxic but odorless gas. Additionally, radioactive palladium is under investigation for use in cancer treatment.

Like other platinum group metals, palladium is typically obtained for commercial use as a byproduct from nickel and copper mining and processing, but can also be obtained from ores rich in platinum and from alluvial deposits. Along with ruthenium and rhodium, palladium is a decomposition product of uranium and could theoretically be recovered from spent nuclear fuel, but the problems inherent in working with radioactive materials make this an impractical source for the rare element.


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Palladium is frequently alloyed with gold, silver, iridium and other platinum group elements for use in jewelry. The metal is used in surgical instruments and electrical contacts. Palladium is also an excellent hydrogenation and dehydrogenation catalyst and is available in many organometallic forms for this purpose. High Purity (99.999%) Palladium Oxide (PdO) PowderPalladium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. High Purity (99.999%) Palladium (Pd) Sputtering Target Palladium nanoparticles and nanopowders provide ultra-high surface area. Palladium oxide is available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Palladium fluoride is another insoluble palladium source for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Palladium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Palladium Properties

Palladium(Pd) atomic and molecular weight, atomic number and elemental symbolPalladium is a Block D, Group 10, Period 5 element. Palladium Bohr ModelThe number of electrons in each of palladium's shells is 2, 8, 18, 18 and its electron configuration is [Kr] 4d10. The palladium atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7440-05-3, palladium has a silvery white appearance. Elemental PalladiumPalladium is a member of the platinum group of metals (along with platinum, rhodium, ruthenium, iridium and osmium). Palladium has the lowest melting point and is the least dense of the group. Palladium can occurs as a natural alloy with other platinum-group metals. Nickel-copper deposits are the main commercial source of palladium. Palladium was first discovered by William Hyde Wollaston in 1802.

Symbol: Pd
Atomic Number: 46
Atomic Weight: 106.42
Element Category: transition metal
Group, Period, Block: 10, 5, d
Color: silvery white metallic/ silvery-white
Other Names: Palladio
Melting Point: 1554.9 °C, 2830.82 °F, 1828.05 K
Boiling Point: 2963 °C, 5365 °F, 3236 K
Density: 12.023 g·cm3
Liquid Density @ Melting Point: 10.38 g·cm3
Density @ 20°C: 12.02 g/cm3
Density of Solid: 12023 kg·m3
Specific Heat: 0.24 (kJ/kg K)
Superconductivity Temperature: N/A
Triple Point: 1825 K, 3.5 × 10 3 kPa
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 17.2
Heat of Vaporization (kJ·mol-1): 361.5
Heat of Atomization (kJ·mol-1): 377.4
Thermal Conductivity: 71.8 W·m?1·K?1
Thermal Expansion: (25 °C) 11.8 µm·m-1·K-1
Electrical Resistivity: (20 °C) 105.4 nΩ·m
Tensile Strength: N/A
Molar Heat Capacity: 25.98 J·mol-1·K-1
Young's Modulus: 121 GPa
Shear Modulus: 44 GPa
Bulk Modulus: 180 GPa
Poisson Ratio: 0.39
Mohs Hardness: 4.75
Vickers Hardness: 461 MPa
Brinell Hardness: 310 MPa
Speed of Sound: (20 °C) 3070 m·s-1
Pauling Electronegativity: 2.2
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: 1.35
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: 1.8
Reflectivity (%): 72
Refractive Index: N/A
Electrons: 46
Protons: 46
Neutrons: 60
Electron Configuration: [Kr] 4d10
Atomic Radius: 137 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 139±6 pm
Covalent Radius (Å): 1.3
Van der Waals Radius: 163 pm
Oxidation States: 0, +1, +2, +4, +6 (mildly basic oxide)
Phase: Solid
Crystal Structure: face-centered cubic
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) 54.206
1st Ionization Energy: 520.23 kJ·mol-1
2nd Ionization Energy: 7298.22 kJ·mol-1
3rd Ionization Energy: 11815.13 kJ·mol-1
CAS Number: 5/3/7440
EC Number: 231-115-6
MDL Number: MFCD00011167
Beilstein Number: N/A
SMILES Identifier: [Pd]
InChI Identifier: InChI=1S/Pd
PubChem CID: 23938
ChemSpider ID: 22380
Earth - Total: 0.89 ppm
Mercury - Total: 1.79 ppm
Venus - Total: 0.87 ppm
Earth - Seawater (Oceans), ppb by weight: N/A
Earth - Seawater (Oceans), ppb by atoms: N/A
Earth -  Crust (Crustal Rocks), ppb by weight: 6.3
Earth -  Crust (Crustal Rocks), ppb by atoms: 1
Sun - Total, ppb by weight: 3
Sun - Total, ppb by atoms: 0.04
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: 670
Meterorite (Carbonaceous), ppb by atoms: 130
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: N/A
Universe, ppb by atom: N/A
Discovered By: William Hyde Wollaston
Discovery Date: 1803
First Isolation: William Hyde Wollaston (1803)

Health, Safety & Transportation Information for Palladium

Safety data for Palladium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) palladium.

Safety Data
Signal Word N/A
Hazard Statements N/A
Hazard Codes N/A
Risk Codes N/A
Safety Precautions N/A
RTECS Number N/A
Transport Information N/A
WGK Germany nwg
Globally Harmonized System of
Classification and Labelling (GHS)
Review and Print SDS for Palladium Metal


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Palladium Metal

Product Number: All applicable American Elements product codes, e.g. PD-M-02, PD-M-03, PD-M-04, PD-M-05

CAS #: 7440-05-3

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
The substance is not classified as hazardous to health or the environment according to the CLP regulation.
Classification according to Directive 67/548/EEC or Directive 1999/45/EC
Not applicable
Information concerning particular hazards for human and environment:
No information known.
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
Not applicable
Hazard pictograms
Not applicable
Signal word
Not applicable
Hazard statements
Not applicable
WHMIS classification
Not controlled
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)

Health (acute effects) = 0
Flammability = 0
Physical Hazard = 0
Other hazards
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.


Chemical characterization: Substances
CAS# Description:
7440-05-3 Palladium
Identification number(s):
EC number: 231-115-6


Description of first aid measures
General information
No special measures required.
After inhalation
Seek medical treatment in case of complaints.
After skin contact
Generally the product does not irritate the skin.
After eye contact
Rinse opened eye for several minutes under running water. If symptoms persist, consult a doctor.
After swallowing
If symptoms persist consult doctor.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Metal oxide fume
Advice for firefighters
Protective equipment:
No special measures required.


Personal precautions, protective equipment and emergency procedures
Not required.
Environmental precautions:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow product to reach sewage system or any water course.
Do not allow to penetrate the ground/soil.
Methods and material for containment and cleaning up:
Pick up mechanically.
Prevention of secondary hazards:
No special measures required.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Information about protection against explosions and fires:
No special measures required.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Do not store together with acids.
Store away from oxidizing agents.
Further information about storage conditions:
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
No further data; see section 7.
Control parameters
Components with limit values that require monitoring at the workplace:
The product does not contain any relevant quantities of materials with critical values that have to be monitored at the workplace.
Additional information: No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Maintain an ergonomically appropriate working environment.
Breathing equipment: Not required.
Protection of hands: Not required.
Penetration time of glove material (in minutes)
Not determined
Eye protection: Safety glasses
Body protection: Protective work clothing.


Information on basic physical and chemical properties
General Information
Form: Solid in various forms
Color: Silver grey
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 1554.9 °C (2831 °F)
Boiling point/Boiling range: 3167 °C (5733 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous): Not determined.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure: Not applicable.
Density at 20 °C (68 °F): 12.02 g/cm³ (100.307 lbs/gal)
Relative density: Not determined.
Vapor density: Not applicable.
Evaporation rate: Not applicable.
Solubility in / Miscibility with Water: Insoluble
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


No information known.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
Reacts with strong oxidizing agents
Conditions to avoid
No further relevant information available.
Incompatible materials:
Oxidizing agents
Hazardous decomposition products:
Metal oxide fume


Information on toxicological effects
Acute toxicity: The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity data for components in this product.
LD/LC50 values that are relevant for classification: No data
Skin irritation or corrosion: No irritant effect.
Eye irritation or corrosion: May cause irritation
Sensitization: No sensitizing effects known.
Germ cell mutagenicity: No effects known.
Carcinogenicity: No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity: No effects known.
Specific target organ system toxicity - repeated exposure: No effects known.
Specific target organ system toxicity - single exposure: No effects known.
Aspiration hazard: No effects known.
Subacute to chronic toxicity: No effects known.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow material to be released to the environment without proper governmental permits.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.
Other adverse effects
No further relevant information available


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


Not applicable
UN proper shipping name
Not applicable
Transport hazard class(es)
Not applicable
Packing group
Not applicable
Environmental hazards:
Not applicable.
Special precautions for user
Not applicable.
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):
UN "Model Regulation":


Safety, health and environmental regulations/legislation specific for the substance or mixture National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
REACH - Pre-registered substances
Substance is listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Palladium Isotopes

Naturally occurring palladium (Pd) has four stable isotopes: 104Pd, 105Pd, 106Pd, and 108Pd.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
91Pd 90.94911(61)# 10# ms [>1.5 µs] ß+to 91Rh 7/2+# N/A 731.06 -
92Pd 91.94042(54)# 1.1(3) s [0.7(+4-2) s] ß+to 92Rh 0+ N/A 747.52 -
93Pd 92.93591(43)# 1.07(12) s ß+to 93Rh (9/2+) N/A 760.26 -
94Pd 93.92877(43)# 9.0(5) s ß+to 94Rh 0+ N/A 774.86 -
95Pd 94.92469(43)# 10# s ß+to 95Rh 9/2+# N/A 786.67 -
96Pd 95.91816(16) 122(2) s ß+to 96Rh 0+ N/A 800.33 -
97Pd 96.91648(32) 3.10(9) min ß+to 97Rh 5/2+# N/A 810.28 -
98Pd 97.912721(23) 17.7(3) min ß+to 98Rh 0+ N/A 822.08 -
99Pd 98.911768(16) 21.4(2) min ß+to 99Rh (5/2)+ N/A 831.09 -
100Pd 99.908506(12) 3.63(9) d EC to 100Rh 0+ N/A 841.97 -
101Pd 100.908289(19) 8.47(6) h EC to 101Rh 5/2+ -0.66 857.5 -
102Pd 101.905609(3) Observationally Stable - 0+ N/A 865.58 1.02
103Pd 102.906087(3) 16.991(19) d EC to 103Rh 5/2+ N/A 873.66 -
104Pd 103.904036(4) STABLE - 0+ N/A 881.73 11.14
105Pd 104.905085(4) STABLE - 5/2+ -0.642 889.81 22.33
106Pd 105.903486(4) STABLE - 0+ N/A 897.89 27.33
107Pd 106.905133(4) 6.5(3)E+6 y ß- to 107Ag 5/2+ N/A 905.97 -
108Pd 107.903892(4) STABLE - 0+ N/A 914.05 26.46
109Pd 108.905950(4) 13.7012(24) h ß- to 109Ag 5/2+ N/A 922.13 -
110Pd 109.905153(12) Observationally Stable - 0+ N/A 930.21 11.72
111Pd 110.907671(12) 23.4(2) min ß- to 111Ag 5/2+ N/A 938.28 -
112Pd 111.907314(19) 21.03(5) h ß- to 113Ag 0+ N/A 946.36 -
113Pd 112.91015(4) 93(5) s ß- to 114Ag (5/2+) N/A 945.13 -
114Pd 113.910363(25) 2.42(6) min ß- to 115Ag 0+ N/A 953.2 -
115Pd 114.91368(7) 25(2) s ß- to 116Ag (5/2+)# N/A 961.28 -
116Pd 115.91416(6) 11.8(4) s ß- to 117Ag 0+ N/A 969.36 -
117Pd 116.91784(6) 4.3(3) s ß- to 118Ag (5/2+) N/A 977.44 -
118Pd 117.91898(23) 1.9(1) s ß- to 119Ag 0+ N/A 985.52 -
119Pd 118.92311(32)# 0.92(13) s ß- to 120Ag N/A N/A 984.28 -
120Pd 119.92469(13) 0.5(1) s ß- to 121Ag 0+ N/A 992.36 -
121Pd 120.92887(54)# 400# ms [>300 ns] ß- to 122Ag N/A N/A 1000.44 -
122Pd 121.93055(43)# 300# ms [>300 ns] ß- to 123Ag 0+ N/A 999.2 -
123Pd 122.93493(64)# 200# ms [>300 ns] ß- to 124Ag N/A N/A 1007.28 -
124Pd 123.93688(54)# 100# ms [>300 ns] Unknown 0+ N/A 1015.36 -
125Pd 125 0.44(3) µs / 0.33(4) µs
(2 isomers)
Unknown N/A N/A N/A -
126Pd 126 5.8(8) µs Unknown N/A N/A N/A -