Oxygen Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms compounds (notably oxides) with most elements. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium.
It belongs to group 16 of the periodic table having trivial name chalcogens. You can also download Printable Periodic Table of Elements Flashcards for Oxygen in a PDF format.
Oxygen Facts
Read key information and facts about element Oxygen
| Name | Oxygen |
| Atomic Number | 8 |
| Atomic Symbol | O |
| Atomic Weight | 15.9994 |
| Phase | Gas(Diatomic Gas) |
| Color | Colorless |
| Appearance | - |
| Classification | Other Nonmetal |
| Natural Occurance | Primordial |
| Group in Periodic Table | 16 |
| Group Name | oxygen family |
| Period in Periodic Table | period 2 |
| Block in Periodic Table | p-block |
| Electronic Configuration | [He] 2s2 2p4 |
| Electronic Shell Structure (Electrons per shell) | 2, 6 |
| Melting Point | 54.8 K |
| Boiling Point | 90.2 K |
| CAS Number | CAS7782-44-7 |
How to Locate Oxygen on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 8 to find Oxygen on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Oxygen on periodic table look for cross section of group 16 and period 2 in the modern periodic table.
Oxygen History
The element Oxygen was discovered by W. Scheele in year 1771 in Sweden and United Kingdom. Oxygen was first isolated by W. Scheele in 1771. Oxygen derived its name from the Greek word oxy-, both 'sharp' and 'acid', and -gen, meaning 'acid-forming'.
| Discovered By | W. Scheele |
| Discovery Date | 1771 in Sweden and United Kingdom |
| First Isolation | 1771 |
| Isolated by | W. Scheele |
W. Scheele obtained it 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, but only Lavoisier recognized it as a true element; he named it in 1777.
Oxygen Uses
Many living things, including humans, use oxygen for respiration. Pure oxygen is used to treat breathing problems and make spacecraft livable. Oxygen in the industry is mostly used in manufacturing steel and other metal alloys. Large quantities are also used in the manufacture of chemicals such as nitric acid and hydrogen peroxide. It is also used as an antifreeze and to make polyester and chloroethene, the precursor to PVC. Oxygen gas is used for oxy-acetylene welding. Some of the growing uses is in treating sewage and effluent from the industry.
Oxygen Presence: Abundance in Nature and Around Us
The table below shows the abundance of Oxygen in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
| ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
|---|---|---|
| Abundance in Universe | 10000000 | 800000 |
| Abundance in Sun | 9000000 | 700000 |
| Abundance in Meteorites | 410000000 | 480000000 |
| Abundance in Earth's Crust | 460000000 | 600000000 |
| Abundance in Oceans | 857000000 | 331000000 |
| Abundance in Humans | 610000000 | 240000000 |
Crystal Structure of Oxygen
The solid state structure of Oxygen is Base Centered Monoclinic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
| a | b | c |
|---|---|---|
| 540.3 pm | 342.9 pm | 508.6 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| π/2 | 2.313085 | π/2 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
| Space Group Name | C12/m1 |
| Space Group Number | 12 |
| Crystal Structure | Base Centered Monoclinic |
| Number of atoms per unit cell |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Oxygen Atomic and Orbital Properties
Oxygen atoms have 8 electrons and the electronic shell structure is [2, 6] with Atomic Term Symbol (Quantum Numbers) 3P2.
| Atomic Number | 8 |
| Number of Electrons (with no charge) | 8 |
| Number of Protons | 8 |
| Mass Number | 16 |
| Number of Neutrons | 8 |
| Shell structure (Electrons per energy level) | 2, 6 |
| Electron Configuration | [He] 2s2 2p4 |
| Valence Electrons | 2s2 2p4 |
| Valence (Valency) | 2 |
| Main Oxidation States | -2 |
| Oxidation States | -2, -1, 0, 1, 2 |
| Atomic Term Symbol (Quantum Numbers) | 3P2 |
Bohr Atomic Model of Oxygen - Electrons per energy level
| n | s | p | d | f |
|---|
Ground State Electronic Configuration of Oxygen - neutral Oxygen atom
Abbreviated electronic configuration of Oxygen
The ground state abbreviated electronic configuration of Neutral Oxygen atom is [He] 2s2 2p4. The portion of Oxygen configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [He]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 2s2 2p4, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Oxygen
Complete ground state electronic configuration for the Oxygen atom, Unabbreviated electronic configuration
1s2 2s2 2p4
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
Atomic Structure of Oxygen
Oxygen atomic radius is 48 pm, while it's covalent radius is 73 pm.
| Atomic Radius Calculated | 48 pm(0.48 Å) |
| Atomic Radius Empirical | 60 pm (0.6 Å) |
| Atomic Volume | 22.4134 cm3/mol |
| Covalent Radius | 73 pm (0.73 Å) |
| Van der Waals Radius | 152 pm |
| Neutron Cross Section | 0.00028 |
| Neutron Mass Absorption | 0.000001 |
Spectral Lines of Oxygen - Atomic Spectrum of Oxygen
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.
Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.
Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.
Emission spectrum of Oxygen
Absorption spectrum of Oxygen
Oxygen Chemical Properties: Oxygen Ionization Energies and electron affinity
The electron affinity of Oxygen is 141 kJ/mol.
| Valence | 2 |
| Electronegativity | 3.44 |
| ElectronAffinity | 141 kJ/mol |
Ionization Energy of Oxygen
Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).
Refer to table below for Ionization energies of Oxygen
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1st | 1313.9 |
| 2nd | 3388.3 |
| 3rd | 5300.5 |
| 4th | 7469.2 |
| 5th | 10989.5 |
| 6th | 13326.5 |
| 7th | 71330 |
| 8th | 84078 |
Oxygen Physical Properties
Refer to below table for Oxygen Physical Properties
| Density | 0.001429 g/cm3 |
| Molar Volume | 22.4134 cm3/mol |
Elastic Properties
| Young Modulus | - |
| Shear Modulus | - |
| Bulk Modulus | - |
| Poisson Ratio | - |
Hardness of Oxygen - Tests to Measure of Hardness of Element
| Mohs Hardness | - |
| Vickers Hardness | - |
| Brinell Hardness | - |
Oxygen Electrical Properties
Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).
Oxygen is a -. Refer to table below for the Electrical properties of Oxygen
| Electrical conductors | - |
| Electrical Conductivity | - |
| Resistivity | - |
| Superconducting Point | - |
Oxygen Heat and Conduction Properties
| Thermal Conductivity | 0.02658 W/(m K) |
| Thermal Expansion | - |
Oxygen Magnetic Properties
| Magnetic Type | Paramagnetic |
| Curie Point | - |
| Mass Magnetic Susceptibility | 0.000001335 m3/kg |
| Molar Magnetic Susceptibility | 4.27184e-8 m3/mol |
| Volume Magnetic Susceptibility | 0.00000190772 |
Optical Properties of Oxygen
| Refractive Index | 1.000271 |
Acoustic Properties of Oxygen
| Speed of Sound | 317.5 m/s |
Oxygen Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Oxygen
| Melting Point | 54.8 K(-218.35 °C, -361.030 °F) |
| Boiling Point | 90.2 K(-182.95 °C, -297.310 °F) |
| Critical Temperature | 154.59 K |
| Superconducting Point | - |
Enthalpies of Oxygen
| Heat of Fusion | 0.222 kJ/mol |
| Heat of Vaporization | 3.41 kJ/mol |
| Heat of Combustion | - |
Oxygen Isotopes - Nuclear Properties of Oxygen
Oxygen has 17 isotopes, with between 12 and 28 nucleons. Oxygen has 3 stable naturally occuring isotopes.
Isotopes of Oxygen - Naturally occurring stable Isotopes: 16O, 17O, 18O.
| Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|---|---|
| 12O | 8 | 4 | 12 | Synthetic | ||
| 13O | 8 | 5 | 13 | Synthetic | ||
| 14O | 8 | 6 | 14 | Synthetic | ||
| 15O | 8 | 7 | 15 | Synthetic | ||
| 16O | 8 | 8 | 16 | 99.757% | Stable | |
| 17O | 8 | 9 | 17 | 0.038% | Stable | N/A |
| 18O | 8 | 10 | 18 | 0.205% | Stable | N/A |
| 19O | 8 | 11 | 19 | Synthetic | ||
| 20O | 8 | 12 | 20 | Synthetic | ||
| 21O | 8 | 13 | 21 | Synthetic | ||
| 22O | 8 | 14 | 22 | Synthetic | ||
| 23O | 8 | 15 | 23 | Synthetic | ||
| 24O | 8 | 16 | 24 | Synthetic | ||
| 25O | 8 | 17 | 25 | Synthetic | ||
| 26O | 8 | 18 | 26 | Synthetic | ||
| 27O | 8 | 19 | 27 | Synthetic | ||
| 28O | 8 | 20 | 28 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.
| DOT Numbers | 1073 |
| DOT Hazard Class | 2.2 |
NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.
The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.
| NFPA Fire Rating | 0 | Will not burn |
| NFPA Health Rating | 3 | Flash Points below 37.8°C (100°F) |
| NFPA Reactivity Rating | 2 | Flash Points Above 37.8°C (100°F) not exceeding 93.3°C (200°F) |
| NFPA Hazards | OX | Oxidizing Agent |
| Autoignition Point | - |
| Flashpoint | - |
Database Search
List of unique identifiers to search the element in various chemical registry databases
| Database | Identifier number |
|---|---|
| CAS Number - Chemical Abstracts Service (CAS) | CAS7782-44-7 |
| RTECS Number | RTECSRS2060000 |
| CID Number | CID977 |
| Gmelin Number | - |
| NSC Number | - |
Compare Oxygen with other elements
Compare Oxygen with Group 16, Period 2 and Other Nonmetal elements of the periodic table.
Compare Oxygen with all Group 16 elements
Compare Oxygen with all Period 2 elements
Compare Oxygen with all Other Nonmetal elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Oxygen