Skip to Main Content

About Aluminum

Aluminum Bohr Model

Compounds called alums--latin for “bitter salt”-- were used in dyes and wound dressings in ancient Greece and Rome. When the existence of a base metal of these salts was recognized in 1808 by Humphry Davy, he named it "alumium," which was eventually changed to "aluminum." Aluminum metal was first purified by another chemist in 1825, but it was initially very difficult to extract the metal from ore, and for some years this made pure aluminum very valuable. In the late 1880’s, two independent chemists developed what came to be known as the Hall-Heroult process for extracting aluminum from minerals, making extraction much more economical and bringing the metal into more general use.

Aluminum is the third most abundant element in the earth’s crust and the most abundant metal. As such, the element and its compounds have practically innumerable applications. The elemental metal is durable, lightweight, ductile, and malleable, and therefore can be easily formed using a variety of metalworking techniques. However, pure aluminum is soft and lacking in strength, and therefore alloys of aluminum with other metals are generally used for most applications--even household aluminum foil and aluminum beverage cans are generally produced from alloys. Aluminum alloys are generally less dense than alternative metals of similar strength, and thus are particularly useful in applications where a strong but lightweight structure is needed. These alloys are used in the construction of vehicles and buildings, and are frequently the casing material for small electronics. Additionally, aluminum is a component of the magnetic alloys MKM steel and Alnico, which are both used to produce permanent magnets for a variety of uses. Aluminum is also a good thermal and electrical conductor, leading it to find uses as heatsinks and wiring in electronics.

Aluminum oxide, often called alumina, is one of the most common aluminum compounds. Its crystalline form occurs naturally as corundum, high-quality forms of which are used as gemstones and considered either rubies or sapphires depending on the colors imparted by trace impurities. These gems are the hardest natural substances after diamond, and are therefore extremely resistant to scratching. Synthetic versions are used in optical devices such as spectroscopes and lasers, shatter resistant windows, and as insulating substrates for silicon integrated circuits. Powdered forms of aluminum oxide are used as filler in plastics, as it is both white and fairly chemically inert. The same properties lead to its use in sunscreens and cosmetic products. The powder is also used as an abrasive in industrial and commercial applications from sandpaper to toothpaste, and as a catalyst or catalyst support for some industrial chemical processes. Alumina may be used in the production of zirconia aluminia, an extremely strong and corrosion resistant class of composite ceramics that are used in cutting tools and medical implants. Finally, alumina fibers are components of many experimental and a few commercial fiber composite materials, and alumina nanofibers specifically have attracted a great deal of research interest.

Aluminum silicates are also aluminum compounds of considerable commercial importance. A number of aluminosilicates occur naturally, often as microporous minerals known as zeolites or hydrated clay minerals such as kaolin. Natural zeolites can be used industrially, but most applications use synthetic zeolites. Zeolites are notable for their very regular pore sizes, which allow them to act as molecular sieves, separating mixtures based on particle size.This property is exploited for applications in water purification, research chemistry, and the precise separation of gases from mixed gas streams. Additionally, the mineral’s porous nature allows it to filter select ions from nuclear waste, which can then be trapped permanently by pressing the mineral into a non-porous durable ceramic. Zeolites can also efficiently store heat, and are therefore used in heating, refrigeration, and energy storage applications. The high surface area provided by the porous material makes zeolites an excellent catalyst support material. Additionally, zeolites are used in laundry detergent, concrete and cement, medical applications, agriculture, and in aquarium filters and cat litter. Aluminosilicates are also frequently used to produce ceramics; notably, kaolin clay is the base material for the well-known ceramic porcelain.

There are many other notable aluminum compounds. Aluminum sulfates and alums are used in water treatment, paper manufacturing, fabric dying, fireproofing, and leather tanning. Aluminum chloride is used as a catalyst in oil refining and the production of synthetic rubber and polymers, while aluminum chlorohydrate is used in antiperspirants and in water treatment applications. Aluminum is a component of the semiconductor aluminum gallium arsenide, which is often used alongside gallium arsenide in semiconductor devices, and of antimony-aluminum phase change material used in phase-change memory devices. Lanthanum aluminate is a perovskite ceramic that is of interest for use as a substrate for the growth of superconducting thin-films, and as a gate dielectric for use in next-generation metal oxide semiconductor field-effect transistors (MOSFETs).

Aluminum has a strong affinity for oxygen and is therefore rarely found in its pure state in nature. It is instead found primarily as oxides and silicates, and the primary commercial ore of aluminum is a mix of minerals known as bauxite. The Hall-Heroult process developed in the 19th century is still used today for the processing of aluminum ore. The process requires a significant amount of energy input, but all proposed alternatives have either been less viable economically or were ruled out due to environmental concerns. Since aluminum can be recycled for a fraction of the energy cost of removing new aluminum from ore, aluminum recycling is cost effective and practiced widely. The “secondary” aluminum produced from recycling therefore accounts for a sizable percentage of the aluminum used each year. Additionally, a number of aluminum-containing minerals are mined for direct use or use as compounds, rather than for extraction of metallic aluminum.


Featured High Purity Products
Semiconductor & Optical
Sputtering Targets
+ Open All
- Close All

Aluminum is available as metal and compounds with purities from 99% to 99.9999% (ACS grade to ultra-high purity) in the form of foils, sputtering targets, and nanopowders. Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes.High Purity (99.999%) Aluminum Oxide (Al2O3) Powder Aluminum oxide is available in forms including powders and dense pellets for such uses as optical coating and thin film applications. High Purity (99.9999%) Aluminum (Al) Sputtering Target Aluminum is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries. Aluminum may be synthesized in ultra-high purity (99.999+%) forms for laboratory standards, advanced electronic, thin film deposition using sputtering targets and evaporation materials, metallurgy and optical materials and other high technology applications. Organometallic aluminum compounds are soluble in organic or non-aqueous solvents. Information is provided for stable (non-radioactive) aluminum isotopes in the isotopes tab above. See Analytical Services for information on available certified chemical and physical analysis techniques including MS-ICP, X-Ray Diffraction, PSD and Surface Area (BET) analysis.

Aluminum Properties

Elemental AluminumAluminum (Al) atomic and molecular weight, atomic number and elemental symbolAluminum, also known as Aluminium, is a Block P, Group 13, Period 3 element. It is the third most abundant element in the earth's crust and the most abundant metallic element. In its elemental form, CAS 7429-90-5, Aluminum has a silvery gray metallic appearance. Pure aluminum is soft and lacks strength, but alloyed with small amounts of copper, magnesium, silicon, manganese, or other elements it has extraordinarily useful properties. Aluminum Bohr ModelIt is light, nonmagnetic and non-sparking. It is second among metals in the scale of malleability, and sixth in ductility. Metallic aluminum was first predicted to be a component of alum salts in 1808 by Humphry Davy, and was first isolated in pure form by Friedrich Wöhler in 1827.

Symbol: Al
Atomic Number: 13
Atomic Weight: 26.98
Element Category: post-transition metal
Group, Period, Block: 13, 3, p
Color: silvery
Other Names: Aluminium; Alluminio
Melting Point: 660.32 °C, 1220.58 °F
Boiling Point: 2519 °C, 4566 °F
Density: 2.70 g/cm3
Liquid Density @ Melting Point: 2.375 g/cm3
Density @ 20°C: 2.702 g/cm3
Density of Solid: 2700 kg·m3
Specific Heat: 0.91 (kJ/kg K)
Superconductivity Temperature: 1.175 [or -271.975 °C (-457.55 °F)] K
Triple Point: N/A
Critical Point: 7,577 °C (7,850 K) , Mpa
Heat of Fusion (kJ·mol-1): 10.67
Heat of Vaporization (kJ·mol-1): 290.8
Heat of Atomization (kJ·mol-1): 324.01
Thermal Conductivity: 237 W·m-1·K-1
Thermal Expansion: (25 °C) 23.1 µm·m-1·K-1
Electrical Resistivity: (20 °C) 28.2 nΩ·m
Tensile Strength: 6800 psi Coldroled 16,000 psi.
Molar Heat Capacity: 24.200 J·mol-1·K-1
Young's Modulus: 70 GPa
Shear Modulus: 26 GPa
Bulk Modulus: 76 GPa
Poisson Ratio: 0.35
Mohs Hardness: 2.75
Vickers Hardness: 167 MPa
Brinell Hardness: 245 MPa
Speed of Sound: r.t. (rolled) 5,000 m·s-1
Pauling Electronegativity: 1.61
Sanderson Electronegativity: 1.71
Allred Rochow Electronegativity: 1.47
Mulliken-Jaffe Electronegativity: 1.83 (sp2 orbital)
Allen Electronegativity: 1.613
Pauling Electropositivity: 2.39
Reflectivity (%): 71
Refractive Index: N/A
Electrons: 13
Protons: 13
Neutrons: 14
Electron Configuration: [Ne] 3s2 3p1
Atomic Radius: 143 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 121 ± 4 pm
Covalent Radius (Å): 1.24
Van der Waals Radius: 184 pm
Oxidation States: 3,2,1 (amphoteric oxide)
Phase: Solid
Crystal Structure: face-centered cubic
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) 41.747
1st Ionization Energy: 577.54 kJ·mol-1
2nd Ionization Energy: 1816.69 kJ·mol-1
3rd Ionization Energy: 2744.80 kJ·mol-1
CAS Number: 7429-90-5
EC Number: 231-072-3
MDL Number: MFCD00134029
Beilstein Number: N/A
SMILES Identifier: [Al]
InChI Identifier: InChI=1S/Al
PubChem CID: 5359268
ChemSpider ID: 4514248
Earth - Total: 1.41%
Mercury - Total: 1.08%
Venus - Total: 1.48%
Earth - Seawater (Oceans), ppb by weight: 5
Earth - Seawater (Oceans), ppb by atoms: 1.1
Earth -  Crust (Crustal Rocks), ppb by weight: 82000000
Earth -  Crust (Crustal Rocks), ppb by atoms: 63000000
Sun - Total, ppb by weight: 60000
Sun - Total, ppb by atoms: 3000
Stream, ppb by weight: 400
Stream, ppb by atoms: 15
Meterorite (Carbonaceous), ppb by weight: 9300000
Meterorite (Carbonaceous), ppb by atoms: 6700000
Typical Human Body, ppb by weight: 900
Typical Human Body, ppb by atom: 210
Universe, ppb by weight: 50000
Universe, ppb by atom: 2000
Discovered By: Sir Humphrey Davy
Discovery Date: 1812
First Isolation: Friedrich Wöhler (1827)

Health, Safety & Transportation Information for Aluminum

Safety data for aluminum metal, nanoparticles, and 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 aluminum material or compound referenced in the “Products” tab. The below information applies to elemental (metallic) Aluminum.

Safety Data
Signal Word Warning
Hazard Statements H228
Hazard Codes F
Risk Codes 11
Safety Precautions N/A
RTECS Number BD0330000
Transport Information UN 1396 4.3/PG 2
WGK Germany nwg
Globally Harmonized System of
Classification and Labelling (GHS)
Review and Print SDS Aluminum Metal


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


Product Name: Aluminum Metal

Product Number: All applicable American Elements product codes, e.g. AL-M-02, AL-M-03, AL-M-04, AL-M-05, AL-M-06

CAS #: 7429-90-5

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
Not applicable.
Not applicable


Chemical characterization: Substances
CAS# Description:
7429-90-5 Aluminum
Identification number(s):
EC number:


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:
7429-90-5 Aluminum (100.0%)
PEL (USA) Long-term value: 15*; 15** mg/m³
*Total dust; ** Respirable fraction
REL (USA) Long-term value: 10* 5** mg/m³
*Total dust **Respirable fraction
TLV (USA) Long-term value: 1* mg/m³
as Al; *as respirable fraction
EL (Canada) Long-term value: 1.0 mg/m³
metal and insoluble compdounds, respirable
EV (Canada) Long-term value: 5 mg/m³
aluminium-containing (as aluminium)
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-colored
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 660.4 °C (1221 °F)
Boiling point/Boiling range: 2519 °C (4566 °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): 2.7 g/cm³ (22.532 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:
No effects known.
LD/LC50 values that are relevant for classification:
No data
Skin irritation or corrosion:
May cause irritation
Eye irritation or corrosion:
May cause irritation
No sensitizing effects known.
Germ cell mutagenicity:
No effects known.
ACGIH A4: Not classifiable as a human carcinogen: Inadequate data on which to classify the agent in terms of its carcinogenicity in humans and/or animals.
Reproductive toxicity:
The Registry of Toxic Effects of Chemical Substances(RTECS) contains reproductive data for this substance.
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:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains multiple dose toxicity
data for this substance.
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
Not applicable.
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):


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)
7429-90-5 Aluminum
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.
This product is subject to the reporting requirements of section 313 of the Emergency Planning and Community Right to Know Act of 1986 and 40CFR372.
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.

Aluminum Isotopes

Aluminum has 22 known isotopes from 21Al to 42Al. Of the 22, only 27Al (stable isotope) and 26Al (radioactive isotope; t1/2 = 0.72x106 yr) occur naturally. 26Al is produced from argon in the atmosphere by spallation caused by cosmic-ray protons. 26Al and 27Al have several practical applications; for example, dating of marine sediments, glacial ice, and meteorites. The ratio of 26Al to 10Be has been used to study the role of transport, deposition, sediment storage and burial times, and erosion on 105 to 106 yr timescales.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
21Al 21.02804(32)# <35 ns p to 20Mg 1/2+# N/A 128.98 -
22Al 22.01952(10)# 59(3) ms ß+ to 22Mg; ß+ + 2p to 20Ne; ß+ + p to 21Na (3)+ N/A 145.44 -
23Al 23.007267(20) 470(30) ms ß+ to 23Mg; ß+ + p to 22Na 5/2+# N/A 164.7 -
24Al 23.9999389(30) 2.053(4) s EC + a to 20Ne; EC to 24Mg 4+ 3.646 180.23 -
25Al 24.9904281(5) 7.183(12) s EC to 25Mg 5/2+ N/A 196.7 -
26Al 25.98689169(6) 7.17(24)E+5 y EC to 26Mg 5+ N/A 208.5 -
27Al 26.98153863(12) STABLE - 5/2+ 3.641504 221.24 100
28Al 27.98191031(14) 2.2414(12) min ß- to 28Si 3+ 3.24 229.32 -
29Al 28.9804450(13) 6.56(6) min ß- to 29Si 5/2+ N/A 238.33 -
30Al 29.982960(15) 3.60(6) s ß- to 30Si 3+ N/A 244.54 -
31Al 30.983947(22) 644(25) ms ß- to 31Si; ß- + n to 30Si (3/2,5/2)+ N/A 251.69 -
32Al 31.98812(9) 31.7(8) ms ß- to 32Si; ß- + n to 31Si 1+ N/A 255.11 -
33Al 32.99084(8) 41.7(2) ms ß- to 33Si; ß- + n to 32Si (5/2+)# N/A 261.33 -
34Al 33.99685(12) 56.3(5) ms ß- to 34Si; ß- + n to 33Si 4-# N/A 263.82 -
35Al 34.99986(19) 38.6(4) ms ß- to 35Si; ß- + n to 34Si 5/2+# N/A 269.1 -
36Al 36.00621(23) 90(40) ms ß- to 36Si; ß- + n to 35Si N/A N/A 270.66 -
37Al 37.01068(36) 10.7(13) ms ß- to 37Si 3/2+ N/A 275.01 -
38Al 38.01723(78) 7.6(6) ms ß- to 38Si N/A N/A 276.57 -
39Al 39.02297(158) 7.6(16) ms ß- to 39Si 3/2+# N/A 279.99 -
40Al 40.03145(75)# 10# ms [>260 ns] Unknown N/A N/A 279.68 -
41Al 41.03833(86)# 2# ms [>260 ns] Unknown 3/2+# N/A 281.24 -
42Al 42.04689(97)# 1# ms Unknown N/A N/A 281.86 -