Oxygen (O)

Oxygen is the 8th element in the periodic table and has a symbol of O and atomic number of 8. It has an atomic weight of 15.999 and a mass number of 16. Oxygen has eight protons and eight neutrons in its nucleus, and eight electrons in two shells. It is located in group sixteen, period two and block p of the periodic table. A colourless, odourless gaseous element belonging to group 16 of the periodic table. It is the most abundant element present in the earth's crust. It also makes up 20.8% of the Earth's atmosphere. For industrial purposes, it is separated from liquid air by fractional distillation. It is used in high temperature welding, and in breathing. It commonly comes in the form of Oxygen, but is found as Ozone in the upper atmosphere. It was discovered by Priestley in 1774.

Atomic Number	8
Atomic Weight	15.999
Mass Number	16

Group	16
Period	2
Block	p

Protons	8 p⁺
Neutrons	8 n⁰
Electrons	8 e^-

Properties

Physical Properties
Atomic Radius	60 pm 171 pm
Molar Volume	14 cm³/mol
Covalent Radius	63 pm 57 pm 53 pm 65 pm 66 pm
Metallic Radius
Ionic Radius	135 pm 136 pm 138 pm 140 pm 142 pm
Crystal Radius	121 pm 122 pm 124 pm 126 pm 128 pm
Van der Waals Radius	155 pm 152 pm 340.46 pm 152 pm 182 pm 158 pm 350 pm
Density	0.001308 g/cm³
Energy
Proton Affinity	485.2 kJ/mol
Electron Affinity	1.4611135 eV/particle
Ionization Energy	13.618054 eV/particle 35.12111 eV/particle 54.93554 eV/particle 77.4135 eV/particle 113.8989 eV/particle 138.1189 eV/particle 739.32679 eV/particle 871.40985 eV/particle

Heat of Vaporization
Heat of Fusion
Heat of Formation	249.229 kJ/mol
Electrons
Electron Shells	2, 6

Valence Electrons	6

Electron Configuration	[He] 2s² 2p⁴

Oxidation States	-2, -1, 0, 1, 2
Electronegativity	21.36 eV/particle 0.304575 3.44
Electrophilicity	2.337978174823841 eV/particle
Phases
Phase	Gas
Gas Phase	Diatomic
Boiling Point	90.188 K
Melting Point	54.36 K
Critical Pressure	5.043 MPa
Critical Temperature	154.581 K
Triple Point	54.3584 K 0.1463 kPa
Visual
Oxygen is a Colorless. O has a CPK of #f00000, Jmol of #ff0d0d, and MOLCAS GV of #f32e42. The Refractive Index of Element 8 is 1.000271.
Color	Colorless #f00000 #ff0d0d #f32e42
Appearance
Refractive Index	1.000271
Thermodynamic Properties
Thermal Conductivity	0.027 W/(m K)
Thermal Expansion
Molar Heat Capacity	29.378 J/(mol K)
Specific Heat Capacity	0.918 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)	7/5
Electrical Properties
Type
Electrical Conductivity
Electrical Resistivity
Superconducting Point
Magnetism
Type	paramagnetic
Magnetic Susceptibility (Mass)	0.000001335 m³/Kg
Magnetic Susceptibility (Molar)	0.0000000427184 m³/mol
Magnetic Susceptibility (Volume)	0.00000190772
Magnetic Ordering
Curie Point
Neel Point
Structure
The Crystal Structure of Oxygen is CUB. The lattice constant of O is 6.83 Å. The lattice angles of Element 8 are π/2, 2.313085, π/2.
Crystal Structure	Base Centered Monoclinic (CUB)
Lattice Constant	6.83 Å
Lattice Angles	π/2, 2.313085, π/2
Mechanical Properties
The Speed of Sound of Oxygen is 317.5 m/s.
Hardness
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound	317.5 m/s
Classification
The CAS Group of Oxygen is VIB. The IUPAC Group of O is VIA. The Glawe Number of Element 8 is 97. The Mendeleev Number of Oxygen (O) is 99. The Pettifor Number of Oxygen is 101. The Geochemical Class of O is major. The Goldschmidt Class of Element 8 is litophile.
Category	Other nonmetals, Nonmetals
CAS Group	VIB
IUPAC Group	VIA
Glawe Number	97
Mendeleev Number	99
Pettifor Number	101
Geochemical Class	major
Goldschmidt Class	litophile
Other
The Gas Basicity of Oxygen is 459.6 kJ/mol. The Dipole Polarizability of O is 5.3 plus or minus 0.2 a₀. Element 8 has a C6 Dispersion Coefficient (CD) of 15.6 a₀, and C6 Dispersion Coefficient (GB) of 16.7 a₀. The Allotropes of Oxygen (O) are Dioxygen, Ozone, Tetraoxygen. The Neutron Cross Section of Oxygen is 0.00028. The Neutron Mass Absorption of O is 1.0E-6. The Quantum Numbers of Element 8 is 3P2. The Space Group of Oxygen (O) is 12 (C12/m1).
Gas Basicity	459.6 kJ/mol
Dipole Polarizability	5.3 ± 0.2 a₀
C6 Dispersion Coefficient	15.6 a₀ 16.7 a₀
Allotropes	Dioxygen, Ozone, Tetraoxygen
Neutron Cross Section	0.00028
Neutron Mass Absorption	0.000001
Quantum Numbers	3P2
Space Group	12 (C12/m1)

Isotopes of Oxygen

Stable Isotopes	3
Unstable Isotopes	15
Radioactive Isotopes	13

¹¹O

Abundance	Radioactive ☢️
Relative Atomic Mass	11.051249828 ± 0.000064453 Da
Mass Number	11
G-Factor
Half Life	198 ± 12 ys
Spin	3/2
Quadrupole Moment
Discovery Year	2019
Parity	-

¹¹O Decay Modes

Decay Mode	Intensity
2p (2-proton emission)	100%

¹²O

Abundance	Radioactive ☢️
Relative Atomic Mass	12.034367726 ± 0.000012882 Da
Mass Number	12
G-Factor	0
Half Life	8.9 ± 3.3 zs
Spin	0
Quadrupole Moment	0
Discovery Year	1978
Parity	+

¹²O Decay Modes

Decay Mode	Intensity
2p (2-proton emission)	100%

¹³O

Abundance	Radioactive ☢️
Relative Atomic Mass	13.024815435 ± 0.000010226 Da
Mass Number	13
G-Factor	0.92613333333333 ± 0.0002
Half Life	8.58 ± 0.05 ms
Spin	3/2
Quadrupole Moment	0.0111 ± 0.0008
Discovery Year	1963
Parity	-

¹³O Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ p (β⁺-delayed proton emission)	10.9%

¹⁴O

Abundance	Radioactive ☢️
Relative Atomic Mass	14.008596706 ± 0.000000027 Da
Mass Number	14
G-Factor	0
Half Life	70.621 ± 0.011 s
Spin	0
Quadrupole Moment	0
Discovery Year	1949
Parity	+

¹⁴O Decay Modes

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

¹⁵O

Abundance	Radioactive ☢️
Relative Atomic Mass	15.003065636 ± 0.000000526 Da
Mass Number	15
G-Factor	1.43816 ± 0.00024
Half Life	122.266 ± 0.043 s
Spin	1/2
Quadrupole Moment	0
Discovery Year	1934
Parity	-

¹⁵O Decay Modes

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

¹⁶O

Abundance	99.757 ± 0.011
Relative Atomic Mass	15.99491461926 ± 0.00000000032 Da
Mass Number	16
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1919
Parity	+

¹⁷O

Abundance	0.03835 ± 0.00096
Relative Atomic Mass	16.99913175595 ± 0.00000000069 Da
Mass Number	17
G-Factor	-0.7574172 ± 0.000004
Half Life
Spin	5/2
Quadrupole Moment
Discovery Year	1925
Parity	+

¹⁸O

Abundance	0.2045 ± 0.0102
Relative Atomic Mass	17.99915961214 ± 0.00000000069 Da
Mass Number	18
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1929
Parity	+

¹⁹O

Abundance	Radioactive ☢️
Relative Atomic Mass	19.003577969 ± 0.00000283 Da
Mass Number	19
G-Factor	0.612952 ± 0.000028
Half Life	26.47 ± 0.006 s
Spin	5/2
Quadrupole Moment	0.00362 ± 0.00013
Discovery Year	1936
Parity	+

¹⁹O Decay Modes

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

²⁰O

Abundance	Radioactive ☢️
Relative Atomic Mass	20.004075357 ± 0.00000095 Da
Mass Number	20
G-Factor	0
Half Life	13.51 ± 0.05 s
Spin	0
Quadrupole Moment	0
Discovery Year	1959
Parity	+

²⁰O Decay Modes

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

²¹O

Abundance	Radioactive ☢️
Relative Atomic Mass	21.008654948 ± 0.000012882 Da
Mass Number	21
G-Factor
Half Life	3.42 ± 0.1 s
Spin	5/2
Quadrupole Moment
Discovery Year	1968
Parity	+

²¹O Decay Modes

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

²²O

Abundance	Radioactive ☢️
Relative Atomic Mass	22.009965744 ± 0.000061107 Da
Mass Number	22
G-Factor	0
Half Life	2.25 ± 0.09 s
Spin	0
Quadrupole Moment	0
Discovery Year	1969
Parity	+

²²O Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	22%

²³O

Abundance	Radioactive ☢️
Relative Atomic Mass	23.015696686 ± 0.000130663 Da
Mass Number	23
G-Factor
Half Life	97 ± 8 ms
Spin	1/2
Quadrupole Moment	0
Discovery Year	1970
Parity	+

²³O Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	7%

²⁴O

Abundance	Radioactive ☢️
Relative Atomic Mass	24.019861 ± 0.000177 Da
Mass Number	24
G-Factor	0
Half Life	77.4 ± 4.5 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1970
Parity	+

²⁴O Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
β⁻ n (β⁻-delayed neutron emission)	43%

²⁵O

Abundance	Radioactive ☢️
Relative Atomic Mass	25.029338919 ± 0.000177225 Da
Mass Number	25
G-Factor
Half Life	5.18 ± 0.35 zs
Spin	3/2
Quadrupole Moment
Discovery Year	2008
Parity	+

²⁵O Decay Modes

Decay Mode	Intensity
n (neutron emission)	100%

²⁶O

Abundance	Radioactive ☢️
Relative Atomic Mass	26.037210155 ± 0.000177081 Da
Mass Number	26
G-Factor	0
Half Life	4.2 ± 3.3 ps
Spin	0
Quadrupole Moment	0
Discovery Year	2012
Parity	+

²⁶O Decay Modes

Decay Mode	Intensity
2n (2-neutron emission)	100%

²⁷O

Abundance
Relative Atomic Mass	27.047955 ± 0.000537 Da
Mass Number	27
G-Factor
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year
Parity	+

²⁷O Decay Modes

Decay Mode	Intensity
n (neutron emission)	%
2n (2-neutron emission)	%

²⁸O

Abundance
Relative Atomic Mass	28.05591 ± 0.00075 Da
Mass Number	28
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year
Parity	+

²⁸O Decay Modes

Decay Mode	Intensity
2n (2-neutron emission)	%
β⁻ (β⁻ decay)	0%

History

Carl Wilhelm Scheele obtained oxygen by heating mercuric oxide and nitrates in 1771, but did not publish his findings until 1777. Joseph Priestley also prepared this new air by 1774. The name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. From the Greek word oxys, acid, and genes, forming

Discoverers	Joseph Priestly, Carl Wilhelm Scheele
Discovery Location	England/Sweden
Discovery Year	1774
Etymology (Name Origin)	Greek: oxys and genes, (acid former).
Pronunciation	OK-si-jen (English)

Oxygen gas can be toxic at elevated partial pressures, leading to convulsions and other health problems

Green and red colors in the Aurora Borealis are caused by oxygen atoms

Uses

Pure oxygen is frequently used to help breathing in patients with respiratory ailments. Oxygen is used in oxyacetylene welding, as an oxidant for rocket fuel, and in methanol and ethylene oxide production. It is also used in the production of steel, plastics and textiles. Plants and animals rely on oxygen for respiration. Used in steel making, welding, and supporting life. Naturally occuring ozone (O3) in the upper atmosphere shields the earth from ultraviolet radiation.

Sources

Obtained primarily from liquid air by fractional distillation. Small amounts are made in the laboratory by electrolysis of water or heating potassium chlorate (KClO3) with manganese dioxide (MnO2) catalyst.

Abundance
Abundance in Earth's crust	461,000 mg/kg
Abundance in Oceans	857,000 mg/L
Abundance in Human Body	61 %
Abundance in Meteor	40 %
Abundance in Sun	0.9 %
Abundance in Universe	1 %

Nuclear Screening Constants

1	s	0.3421
2	p	3.5468
2	s	3.5084

Oxygen on ChemicalAid

ATC code	V03AN01
Art & Architecture Thesaurus ID	300266782
Australian Educational Vocabulary ID	scot/3553
BNCF Thesaurus ID	607
Basque Vikidia ID	Oxigeno
Biblioteca Nacional de España ID	XX534245
Bibliothèque nationale de France ID	11977353d
Brockhaus Enzyklopädie online ID	sauerstoff
ChEBI ID	25805
ChemSpider ID	140526
Cultureel Woordenboek ID	levenswetenschappen-en-geneeskunde/zuurstof
Cultureel Woordenboek ID	natuurkunde-scheikunde-en-sterrenkunde/zuurstof
Den Store Danske ID	ilt
Encyclopædia Britannica Online ID	science/oxygen
Encyclopædia Universalis ID	oxygene
English Vikidia ID	Oxygen
E number	E948
EuroVoc ID	2214
FAST ID	1049616
Freebase ID	/m/025s6bf
French Vikidia ID	Oxygène
GND ID	4051803-6
Golden ID	Oxygen-K46E4
Gran Enciclopèdia Catalana ID	0128751
Great Russian Encyclopedia Online ID	2068059
Italian Vikidia ID	Ossigeno
KBpedia ID	Oxygen
KEGG ID	C00007
Klexikon article ID	Sauerstoff
Krugosvet article	himiya/kislorod
LEM ID	LEM201006799
Latvian National Encyclopedia Online ID	126657
Library of Congress authority ID	sh85096329
MeSH descriptor ID	D010100
NALT ID	8381
NDL Authority ID	00570181
NE.se ID	syre
NKCR AUT ID	ph122069
Namuwiki ID	산소
National Library of Israel J9U ID	987007555738105171
OmegaWiki Defined Meaning	2698
OpenAlex ID	C540031477
OpenAlex ID	C3020088433
OpenAlex ID	C2994492776
OpenAlex ID	C2991788032
OpenAlex ID	C2993183510
PSH ID	5806
Pixiv Encyclopedia ID	酸素
Quora topic ID	Oxygen
Römpp online ID	RD-19-00520
Spanish Vikidia ID	Oxígeno
Store medisinske leksikon ID	oksygen
Store medisinske leksikon ID	oksygen_-_fysiologi
Store norske leksikon ID	oksygen
Treccani ID	ossigeno
UK Archival Thesaurus ID	f2/mt225/4347/1768
UK Parliament thesaurus ID	297787
UNESCO Thesaurus ID	concept4990
USGS Thesaurus ID	1531
WikiSkripta ID	18912
WordNet 3.1 Synset ID	14672278-n
YSA ID	Y95285
YSO ID	11518
Yle topic ID	18-204071
electronic Essential Medicines List medicine ID	4

Oxygen (O)

Properties

Isotopes of Oxygen

11O

11O Decay Modes

12O

12O Decay Modes

13O

13O Decay Modes

14O

14O Decay Modes

15O

15O Decay Modes

16O

17O

18O

19O

19O Decay Modes

20O

20O Decay Modes

21O

21O Decay Modes

22O

22O Decay Modes

23O

23O Decay Modes

24O

24O Decay Modes

25O

25O Decay Modes

26O

26O Decay Modes

27O

27O Decay Modes

28O

28O Decay Modes