Aluminum (Al)

Silvery-white lustrous metallic element of group 3 of the periodic table. Highly reactive but protected by a thin transparent layer of the oxide which quickly forms in air. There are many alloys of aluminum, as well as a good number of industrial uses. Makes up 8.1% of the Earth's crust, by weight. Isolated in 1825 by H.C. Oersted.

Atomic Number	13
Atomic Weight	26.9815385
Mass Number	27

Group	13
Period	3
Block	p

Protons	13 p⁺
Neutrons	14 n⁰
Electrons	13 e^-

Properties

Energy
Atomic Radius	125 pm 239 pm
Molar Volume	10 cm³/mol
Covalent Radius	126 pm 113 pm 111 pm 135 pm 121 pm
Metallic Radius	125 pm 143 pm
Ionic Radius	39 pm 48 pm 53.5 pm
Crystal Radius	53 pm 62 pm 67.5 pm
Van der Waals Radius	210 pm 439 pm 184 pm 236 pm 184 pm 449.9 pm
Density	2.7 g/cm³ 2,375 kg/m³
Proton Affinity
Electron Affinity	0.43283 eV/particle
Ionization Energy	5.9857684 eV/particle 18.82855 eV/particle 28.44764 eV/particle 119.9924 eV/particle 153.8252 eV/particle 190.49 eV/particle 241.76 eV/particle 284.638 eV/particle 330.212 eV/particle 398.65 eV/particle 442.005 eV/particle 2,085.97693 eV/particle 2,304.14 eV/particle

Heat of Vaporization	284.1 kJ/mol
Heat of Fusion	10.75 kJ/mol
Heat of Formation	330.9 kJ/mol
Electrons
Electron Shells	2, 8, 3

Valence Electrons	3

Electron Configuration	[Ne] 3s² 3p¹

Oxidation States	-2, -1, 0, 1, 2, 3
Electronegativity	9.539 eV/particle 0.150078 1.61
Electrophilicity	0.9274010094475963 eV/particle
Phases
Phase	Solid
Gas Phase
Boiling Point	2,792.15 K
Melting Point	933.473 K
Critical Pressure
Critical Temperature	6,700.15 K
Triple Point
Visual
Color	Silver #808090 #bfa6a6 #bfa6a6
Appearance	silvery gray metallic
Refractive Index
Thermodynamic Properties
Thermal Conductivity	237 W/(m K)
Thermal Expansion	0.0000231 1/K
Molar Heat Capacity	24.2 J/(mol K)
Specific Heat Capacity	0.897 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type	Conductor
Electrical Conductivity	38 MS/m
Electrical Resistivity	0.000000026 m Ω
Superconducting Point	1.175 K
Magnetism
Type	paramagnetic
Magnetic Susceptibility (Mass)	0.0000000078 m³/Kg
Magnetic Susceptibility (Molar)	0.00000000021 m³/mol
Magnetic Susceptibility (Volume)	0.0000211
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal Structure	Face Centered Cubic (FCC)
Lattice Constant	4.05 Å
Lattice Angles	π/2, π/2, π/2
Mechanical Properties
Hardness	245 MPa 2.75 MPa 167 MPa
Bulk Modulus	76 GPa
Shear Modulus	26 GPa
Young Modulus	70 GPa
Poisson Ratio	0.35
Speed of Sound	5,100 m/s
Classification
Category	Post-transition metals, Poor metals
CAS Group	IIIB
IUPAC Group	IIIA
Glawe Number	78
Mendeleev Number	82
Pettifor Number	80
Geochemical Class	major
Goldschmidt Class	litophile
Other
Gas Basicity
Dipole Polarizability	57.8 ± 1 a₀
C6 Dispersion Coefficient	528 a₀ 520 a₀
Allotropes
Neutron Cross Section	0.233
Neutron Mass Absorption	0.03
Quantum Numbers	2P1/2
Space Group	225 (Fm_3m)

Isotopes of Aluminum

Stable Isotopes	1
Unstable Isotopes	22
Radioactive Isotopes	21

²¹Al

Abundance
Relative Atomic Mass	21.029082 ± 0.000644 Da
Mass Number	21
G-Factor
Half Life
Spin	5/2
Quadrupole Moment
Discovery Year
Parity	+

²¹Al Decay Modes

Decay Mode	Intensity
p (proton emission)	%

²²Al

Abundance	Radioactive ☢️
Relative Atomic Mass	22.01954 ± 0.00043 Da
Mass Number	22
G-Factor
Half Life	91.1 ± 0.5 ms
Spin	4
Quadrupole Moment
Discovery Year	1982
Parity

²²Al Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	55%
2p (2-proton emission)	1.1%
β⁺α (β⁺-delayed α emission)	0.038%

²³Al

Abundance	Radioactive ☢️
Relative Atomic Mass	23.007244351 ± 0.00000037 Da
Mass Number	23
G-Factor	1.556 ± 0.008
Half Life	446 ± 6 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1969
Parity	+

²³Al Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	1.22%

²⁴Al

Abundance	Radioactive ☢️
Relative Atomic Mass	23.999947598 ± 0.000000244 Da
Mass Number	24
G-Factor
Half Life	2.053 ± 0.004 s
Spin	4
Quadrupole Moment
Discovery Year	1953
Parity	+

²⁴Al Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺α (β⁺-delayed α emission)	0.035%
β⁺ p (β⁺-delayed proton emission)	0.0016%

²⁵Al

Abundance	Radioactive ☢️
Relative Atomic Mass	24.990428308 ± 0.000000069 Da
Mass Number	25
G-Factor	1.45788 ± 0.00048
Half Life	7.1666 ± 0.0023 s
Spin	5/2
Quadrupole Moment	0.24 ± 0.02
Discovery Year	1953
Parity	+

²⁵Al Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

²⁶Al

Abundance	Radioactive ☢️
Relative Atomic Mass	25.986891876 ± 0.000000071 Da
Mass Number	26
G-Factor	0.5606 ± 0.0008
Half Life	717 ± 24 ky
Spin	5
Quadrupole Moment	0.26 ± 0.03
Discovery Year	1934
Parity	+

²⁶Al Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

²⁷Al

Abundance	100
Relative Atomic Mass	26.981538408 ± 0.00000005 Da
Mass Number	27
G-Factor	1.45628 ± 0.000008
Half Life
Spin	5/2
Quadrupole Moment	0.1466 ± 0.001
Discovery Year	1922
Parity	+

²⁸Al

Abundance	Radioactive ☢️
Relative Atomic Mass	27.981910009 ± 0.000000052 Da
Mass Number	28
G-Factor	1.0803333333333 ± 0.0016666666666667
Half Life	2.245 ± 0.005 m
Spin	3
Quadrupole Moment	0.172 ± 0.012
Discovery Year	1934
Parity	+

²⁸Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁹Al

Abundance	Radioactive ☢️
Relative Atomic Mass	28.980453164 ± 0.00000037 Da
Mass Number	29
G-Factor
Half Life	6.56 ± 0.06 m
Spin	5/2
Quadrupole Moment
Discovery Year	1939
Parity	+

²⁹Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

³⁰Al

Abundance	Radioactive ☢️
Relative Atomic Mass	29.982969171 ± 0.000002077 Da
Mass Number	30
G-Factor	1.004 ± 0.0023333333333333
Half Life	3.62 ± 0.06 s
Spin	3
Quadrupole Moment
Discovery Year	1961
Parity	+

³⁰Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

³¹Al

Abundance	Radioactive ☢️
Relative Atomic Mass	30.983949754 ± 0.0000024 Da
Mass Number	31
G-Factor	1.5328 ± 0.002
Half Life	644 ± 25 ms
Spin	5/2
Quadrupole Moment	0.134 ± 0.002
Discovery Year	1971
Parity	+

³¹Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	1.6%

³²Al

Abundance	Radioactive ☢️
Relative Atomic Mass	31.988084338 ± 0.0000077 Da
Mass Number	32
G-Factor	1.953 ± 0.002
Half Life	32.6 ± 0.5 ms
Spin	1
Quadrupole Moment	0.0255 ± 0.0003
Discovery Year	1971
Parity	+

³²Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	0.7%

³³Al

Abundance	Radioactive ☢️
Relative Atomic Mass	32.990877685 ± 0.0000075 Da
Mass Number	33
G-Factor	1.636 ± 0.002
Half Life	41.46 ± 0.09 ms
Spin	5/2
Quadrupole Moment	0.141 ± 0.003
Discovery Year	1971
Parity	+

³³Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	8.5%

³⁴Al

Abundance	Radioactive ☢️
Relative Atomic Mass	33.996781924 ± 0.000002259 Da
Mass Number	34
G-Factor	0.53925 ± 0.004
Half Life	53.73 ± 0.13 ms
Spin	4
Quadrupole Moment
Discovery Year	1977
Parity	-

³⁴Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	26%
2n (2-neutron emission)	%

³⁵Al

Abundance	Radioactive ☢️
Relative Atomic Mass	34.999759816 ± 0.0000079 Da
Mass Number	35
G-Factor
Half Life	38.16 ± 0.21 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1979
Parity	+

³⁵Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	35.8%
2n (2-neutron emission)	%

³⁶Al

Abundance	Radioactive ☢️
Relative Atomic Mass	36.006388 ± 0.0001605 Da
Mass Number	36
G-Factor
Half Life	90 ± 40 ms
Spin
Quadrupole Moment
Discovery Year	1979
Parity

³⁶Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	31%
2n (2-neutron emission)	%

³⁷Al

Abundance	Radioactive ☢️
Relative Atomic Mass	37.010531 ± 0.0001935 Da
Mass Number	37
G-Factor
Half Life	11.4 ± 0.3 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1979
Parity	+

³⁷Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	52%
2n (2-neutron emission)	1%

³⁸Al

Abundance	Radioactive ☢️
Relative Atomic Mass	38.017681 ± 0.000161 Da
Mass Number	38
G-Factor	0
Half Life	9 ± 0.7 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1989
Parity	-

³⁸Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	84%
2n (2-neutron emission)	%

³⁹Al

Abundance	Radioactive ☢️
Relative Atomic Mass	39.02307 ± 0.000322 Da
Mass Number	39
G-Factor
Half Life	7.6 ± 1.6 ms
Spin	5/2
Quadrupole Moment
Discovery Year	1989
Parity	+

³⁹Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	97%
2n (2-neutron emission)	%

⁴⁰Al

Abundance	Radioactive ☢️
Relative Atomic Mass	40.03094 ± 0.000322 Da
Mass Number	40
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year	1996
Parity

⁴⁰Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%

⁴¹Al

Abundance	Radioactive ☢️
Relative Atomic Mass	41.037134 ± 0.000429 Da
Mass Number	41
G-Factor
Half Life
Spin	5/2
Quadrupole Moment
Discovery Year	1997
Parity	+

⁴¹Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%

⁴²Al

Abundance	Radioactive ☢️
Relative Atomic Mass	42.045078 ± 0.000537 Da
Mass Number	42
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year	2007
Parity

⁴²Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%

⁴³Al

Abundance	Radioactive ☢️
Relative Atomic Mass	43.05182 ± 0.000644 Da
Mass Number	43
G-Factor
Half Life
Spin	5/2
Quadrupole Moment
Discovery Year	2007
Parity	+

⁴³Al Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%
β⁻ n (β⁻-delayed neutron emission)	%
2n (2-neutron emission)	%

History

In 1761, Guyton de Morveau proposed the name alumine for the base in alum, and Antoine Lavoisier, in 1787, thought this to be the oxide of a still undiscovered metal. Sir Humphry Davy identified the existence of a metal base of alum in 1808. Hans Christian Ørsted was the first to isolate metallic aluminum in 1825 in impure form. Friedrich Wöhler is generally credited with having isolated the metal in 1827. From the Latin word alumen, alum

Discoverers	Hans Christian Oersted
Discovery Location	Denmark
Discovery Year	1825
Etymology (Name Origin)	Latin: alumen, aluminis, (alum).
Pronunciation	ah-LOO-men-em (English)

Aluminum is not known to be toxic

Aluminum does not stick to magnets under normal conditions

Uses

Aluminum is used in an extensive range of products from drinks cans to window frames and boats to aircraft. It is used in electrical transmission lines. It is also used for kitchen utensils, outside building decoration, and in thousands of industrial applications. When alloyed with small amounts of copper, magnesium, silicon, manganese, or other elements impart a variety of useful properties. Used for many purposes from airplanes to beverage cans. Too soft in its pure form so less than 1% of silicon or iron is added, which hardens and strengthens it.

Sources

Never occurs in free form. Obtained by electrolysis from bauxite (Al2O3).

Abundance
Abundance in Earth's crust	82,300 mg/kg
Abundance in Oceans	0.002 mg/L
Abundance in Human Body	0.00009 %
Abundance in Meteor	0.91 %
Abundance in Sun	0.006 %
Abundance in Universe	0.005 %

Nuclear Screening Constants

1	s	0.409
2	p	4.0366
2	s	4.7864
3	p	8.9344
3	s	8.8828

Aluminum on ChemicalAid

AGROVOC ID	c_317
ASC Leiden Thesaurus ID	29489814X
Art & Architecture Thesaurus ID	300011015
Australian Educational Vocabulary ID	scot/1060
BNCF Thesaurus ID	601
Bibliothèque nationale de France ID	11976300k
Brockhaus Enzyklopädie online ID	aluminium-20
CA PROP 65 ID	aluminum
CAS Registry Number	7429-90-5
CPV Supplementary	AA02
Canadian Encyclopedia article ID	aluminum
ChEBI ID	28984
ChemSpider ID	4514248
CosIng number	32811
DSSTOX compound identifier	DTXCID50875760
DSSTox substance ID	DTXSID3040273
Den Store Danske ID	aluminium
DrugBank ID	01370
ECHA Substance Infocard ID	100.028.248
Encyclopedia of China Online Database ID (Second Edition)	218810
Encyclopædia Britannica Online ID	science/aluminum
Encyclopædia Universalis ID	aluminium
E number	E173
EuroVoc ID	1446
Freebase ID	/m/027vj2v
French Vikidia ID	Aluminium
GND ID	4001573-7
Gran Enciclopèdia Catalana ID	0077291
Gran Enciclopèdia Catalana ID	0001493
Great Russian Encyclopedia Online ID	1816724
Grove Art Online ID	T002160
HCIS ID	139
HCIS ID	140
HSDB ID	507
InChI	InChI=1S/Al
InChIKey	XAGFODPZIPBFFR-UHFFFAOYSA-N
Italian Vikidia ID	Alluminio
KBpedia ID	Aluminum
KEGG ID	C06264
Klexikon article ID	Aluminium
Krugosvet article	nauka_i_tehnika/fizika/ALYUMINI.html
LEM ID	LEM201000405
Latvian National Encyclopedia Online ID	116306
Library of Congress authority ID	sh85003956
LoC and MARC vocabularies ID	mmaterial/alu
MeSH concept ID	M0000824
MeSH descriptor ID	D000535
MinDat mineral ID	107
NALT ID	7265
NKCR AUT ID	ph120753
Namuwiki ID	알루미늄
National Diet Library ID	00560358
National Library of Israel J9U ID	987007294750205171
Nomisma ID	al
OmegaWiki Defined Meaning	149
OpenAlex ID	C513153333
PACTOLS thesaurus ID	pcrtuV4RYc06TP
PM20 ware ID	141969
PSH ID	5792
PubChem CID	5359268
Quora topic ID	Aluminium
RDA value vocabularies ID	RDAMaterial/1003
RKD thesaurus ID	45135
RxNorm ID	1311504
Römpp online ID	RD-01-01786
STW Thesaurus for Economics ID	14293-3
Spanish Cultural Heritage thesauri ID	materias/1000919
Spanish Vikidia ID	Aluminio
Store norske leksikon ID	aluminium
Treccani ID	alluminio
U.S. National Archives Identifier	10637694
UK Archival Thesaurus ID	f2/mt225/4347/7533
UK Parliament thesaurus ID	8321
UNBIS Thesaurus ID	1000253
UNII	CPD4NFA903
UNSPSC Code	11101705
WordNet 3.1 Synset ID	14651998-n
YSO ID	19563
ZVG number	7130
Zhihu topic ID	19632850
archINFORM keyword ID	39

Aluminum (Al)

Properties

Isotopes of Aluminum

21Al

21Al Decay Modes

22Al

22Al Decay Modes

23Al

23Al Decay Modes

24Al

24Al Decay Modes

25Al

25Al Decay Modes

26Al

26Al Decay Modes

27Al

28Al

28Al Decay Modes

29Al

29Al Decay Modes

30Al

30Al Decay Modes

31Al

31Al Decay Modes

32Al

32Al Decay Modes

33Al

33Al Decay Modes

34Al

34Al Decay Modes

35Al

35Al Decay Modes

36Al

36Al Decay Modes

37Al

37Al Decay Modes

38Al

38Al Decay Modes

39Al

39Al Decay Modes

40Al

40Al Decay Modes

41Al

41Al Decay Modes

42Al

42Al Decay Modes

43Al

43Al Decay Modes