TheInfoList

Diatomic molecules are
molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A molecule is an electrically neutral group of two or more atoms held together by chemical bo ...

s composed of only two
atom An atom is the smallest unit of ordinary matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of ato ...

s, of the same or different
chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nu ...
s. The prefix ''di-'' is of Greek origin, meaning "two". If a diatomic molecule consists of two atoms of the same element, such as
hydrogen Hydrogen is the chemical element with the Symbol (chemistry), symbol H and atomic number 1. With a standard atomic weight of , hydrogen is the lightest element in the periodic table. Hydrogen is the abundance of the chemical elements, mos ...

(H2) or
oxygen Oxygen is the chemical element with the chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen Group (periodic table), group in the periodic table, a highly Chemical reaction, reactive nonmetal, and an oxidizing ...

(O2), then it is said to be
homonuclear Homonuclear molecules, or homonuclear species, are molecules composed of only one Chemical element, element. Homonuclear molecules may consist of various numbers of atoms, depending on the element's properties. Some elements form molecules of more t ...
. Otherwise, if a diatomic molecule consists of two different atoms, such as carbon monoxide (CO) or
nitric oxide Nitric oxide ( nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical, i.e., it has an unpaired electron, which is sometimes denoted by a dot i ...

(NO), the molecule is said to be
heteronuclear A heteronuclear molecule is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A molecule is an electrically neutral group of two or ...
. The bond in a homonuclear diatomic molecule is non-polar. The only
chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nu ...
s that form stable homonuclear diatomic molecules at
standard temperature and pressure Standard may refer to: Flags * Colours, standards and guidons * Standard (flag), a type of flag used for personal identification Norm, convention or requirement * Standard (metrology), an object that bears a defined relationship to a unit ...
(STP) (or typical laboratory conditions of 1
bar Bar or BAR may refer to: Food *Bar (establishment) A bar is a long raised narrow table or bench designed for dispensing beer or other alcoholic beverage, alcoholic drinks. They were originally chest high, and a bar, often brass, ran the lengt ...
and 25 °C) are the
gas Gas is one of the four fundamental states of matter (the others being solid, liquid A liquid is a nearly incompressible fluid In physics, a fluid is a substance that continually Deformation (mechanics), deforms (flows) under an appl ...

es
hydrogen Hydrogen is the chemical element with the Symbol (chemistry), symbol H and atomic number 1. With a standard atomic weight of , hydrogen is the lightest element in the periodic table. Hydrogen is the abundance of the chemical elements, mos ...

(H2),
nitrogen Nitrogen is the chemical element with the Symbol (chemistry), symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independentl ...

(N2),
oxygen Oxygen is the chemical element with the chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen Group (periodic table), group in the periodic table, a highly Chemical reaction, reactive nonmetal, and an oxidizing ...

(O2),
fluorine Fluorine is a chemical element with the Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard conditions for temperature and pressure, standard conditions as a highly toxic, pale yellow Diatomic molecule, ...

(F2), and
chlorine Chlorine is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same ...
(Cl2). The
noble gas The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a class of chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In c ...
es (
helium Helium (from el, ἥλιος, Helios, lit=Sun) is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting ...

,
neon Neon is a chemical element with the symbol A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, Object (philosophy), object, or wikt:relationship, relationship. Symbols allow people to go b ...

,
argon Argon is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same num ...
,
krypton Krypton (from grc, κρυπτός, translit=kryptos 'the hidden one') is a chemical element with the symbol (chemistry), symbol Kr and atomic number 36. It is a colorless, odorless, tasteless noble gas that occurs in trace element, tr ...

,
xenon Xenon is a chemical element with the Symbol (chemistry), symbol Xe and atomic number 54. It is a colorless, dense, odorless noble gas found in Atmosphere of Earth, Earth's atmosphere in trace amounts. Although generally unreactive, xe ...

, and
radon Radon is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same number ...

) are also gases at STP, but they are
monatomic In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physics), motion and behavior through Spa ...
. The homonuclear diatomic gases and noble gases together are called "elemental gases" or "molecular gases", to distinguish them from other gases that are
chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entity, molecular entities) composed of atoms from more than one chemical element, element held together by chemical bonds. A homonuclear molecule, mo ...
s. At slightly elevated temperatures, the halogens
bromine Bromine is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same numb ...
(Br2) and
iodine Iodine is a chemical element with the Symbol (chemistry), symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that melts to form a deep violet liq ...

(I2) also form diatomic gases. All halogens have been observed as diatomic molecules, except for
astatine Astatine is a chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all have the same numb ...
and
tennessine Tennessine is a synthetic chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all ...

, which are uncertain. Other elements form diatomic molecules when evaporated, but these diatomic species repolymerize when cooled. Heating ("cracking") elemental phosphorus gives
diphosphorus Diphosphorus is an Inorganic chemistry, inorganic chemical substance, chemical with the chemical formula . Unlike nitrogen, its lighter pnictogen neighbor which forms a stable N2 molecule with a nitrogen to nitrogen triple bond, phosphorus prefers ...
, P2. Sulfur vapor is mostly
disulfur Disulfur is the diatomic molecule Diatomic molecules are molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A molecule is an electr ...
(S2).
Dilithium Dilithium, Li2, is a strongly Electrophile, electrophilic, diatomic molecule comprising two lithium atoms covalent bond, covalently bonded together. Li2 is known in the gas Phase (matter), phase. It has a bond order of 1, an internuclear separati ...
(Li2) and disodium (Na2) are known in the gas phase. Ditungsten (W2) and dimolybdenum (Mo2) form with sextuple bonds in the gas phase. Dirubidium (Rb2) is diatomic.

# Heteronuclear molecules

All other diatomic molecules are
chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entity, molecular entities) composed of atoms from more than one chemical element, element held together by chemical bonds. A homonuclear molecule, mo ...
s of two different elements. Many elements can combine to form
heteronuclear A heteronuclear molecule is a molecule File:Pentacene on Ni(111) STM.jpg, A scanning tunneling microscopy image of pentacene molecules, which consist of linear chains of five carbon rings. A molecule is an electrically neutral group of two or ...
diatomic molecules, depending on temperature and pressure. Examples are gases carbon monoxide (CO),
nitric oxide Nitric oxide ( nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical, i.e., it has an unpaired electron, which is sometimes denoted by a dot i ...

(NO), and
hydrogen chloride The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...

(HCl). Many 1:1
binary compound In materials chemistry, a binary phase or binary compound is a chemical compound containing two different elements. Some binary phase compounds are molecular, e.g. carbon tetrachloride (CCl4). More typically binary phase refers to extended solid ...
s are not normally considered diatomic because they are
polymer A polymer (; Greek ''wikt:poly-, poly-'', "many" + ''wikt:-mer, -mer'', "part") is a Chemical substance, substance or material consisting of very large molecules, or macromolecules, composed of many Repeat unit, repeating subunits. Due to their ...

ic at room temperature, but they form diatomic molecules when evaporated, for example gaseous MgO, SiO, and many others.

# Occurrence

Hundreds of diatomic molecules have been identified in the environment of the Earth, in the laboratory, and in
interstellar space Outer space is the expanse that exists beyond Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. About 29% of Earth's surface is land consisting of continent A continent is ...
Earth's atmosphere File:Atmosphere gas proportions.svg, Composition of Earth's atmosphere by volume, excluding water vapor. Lower pie represents trace gases that together compose about 0.043391% of the atmosphere (0.04402961% at April 2019 concentration ). Number ...

is composed of two species of diatomic molecules: nitrogen (78%) and oxygen (21%). The natural abundance of in the Earth's atmosphere is only of the order of parts per million, but H2 is the most abundant diatomic molecule in the universe. The interstellar medium is dominated by hydrogen atoms.

# Molecular geometry

All diatomic molecules are linear and characterized by a single parameter which is the
bond length Bond or bonds may refer to: Common meanings * Bond (finance) In finance Finance is the study of financial institutions, financial markets and how they operate within the financial system. It is concerned with the creation and management of ...
or distance between the two atoms. Diatomic nitrogen has a triple bond, diatomic oxygen has a double bond, and diatomic hydrogen, fluorine, chlorine, iodine, and bromine all have single bonds.

# Historical significance

Diatomic elements played an important role in the elucidation of the concepts of element, atom, and molecule in the 19th century, because some of the most common elements, such as hydrogen, oxygen, and nitrogen, occur as diatomic molecules.
John Dalton John Dalton (; 6 September 1766 – 27 July 1844) was an English chemist, physicist A physicist is a scientist A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branches of science, ...

's original atomic hypothesis assumed that all elements were monatomic and that the atoms in compounds would normally have the simplest atomic ratios with respect to one another. For example, Dalton assumed water's formula to be HO, giving the atomic weight of oxygen as eight times that of hydrogen, instead of the modern value of about 16. As a consequence, confusion existed regarding atomic weights and molecular formulas for about half a century. As early as 1805,
Gay-Lussac Joseph Louis Gay-Lussac (, , ; 6 December 1778  – 9 May 1850) was a French people, French chemistry, chemist and physics, physicist. He is known mostly for his discovery that water is made of two parts hydrogen and one part oxygen (with Al ...

and von Humboldt showed that water is formed of two volumes of hydrogen and one volume of oxygen, and by 1811
Amedeo Avogadro Lorenzo Romano Amedeo Carlo Avogadro, Count of Quaregna and Cerreto (, also , ; 9 August 17769 July 1856) was an Italian scientist A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branche ...
had arrived at the correct interpretation of water's composition, based on what is now called
Avogadro's law Avogadro's law (sometimes referred to as Avogadro's hypothesis or Avogadro's principle) or Avogadro-Ampère's hypothesis is an experimental gas law The gas laws were developed at the end of the 18th century, when scientists began to realize that ...
and the assumption of diatomic elemental molecules. However, these results were mostly ignored until 1860, partly due to the belief that atoms of one element would have no
chemical affinityIn chemical physics and physical chemistry, chemical affinity is the electronic property by which dissimilar chemical species are capable of forming chemical compounds. Chemical affinity can also refer to the tendency of an atom or compound to comb ...
toward atoms of the same element, and also partly due to apparent exceptions to Avogadro's law that were not explained until later in terms of dissociating molecules. At the 1860
Karlsruhe Congress The Karlsruhe Congress was an international meeting of chemists held in Karlsruhe Karlsruhe (, also , ; formerly spelled Carlsruhe) is the second-largest List of cities and towns in Germany, city of the Germany, German federal state of Baden-Wü ...
on atomic weights, resurrected Avogadro's ideas and used them to produce a consistent table of atomic weights, which mostly agree with modern values. These weights were an important prerequisite for the discovery of the
periodic law Image:Periodic trends.svg, The periodic trends in properties of elements Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativ ...
by
Dmitri Mendeleev Dmitry (russian: Дми́трий); Church Slavic form: Dimitry or Dimitri (); ancient Russian forms: D'mitriy or Dmitr ( or ) is a male given name common in Orthodoxy, Orthodox Christian culture, the Russian version of Greek language, Greek Deme ...
and
Lothar Meyer Julius Lothar Meyer (19 August 1830 – 11 April 1895) was a German chemist. He was one of the pioneers in developing the earliest versions of the periodic table of the chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Pe ...
.

# Excited electronic states

Diatomic molecules are normally in their lowest or ground state, which conventionally is also known as the $X$ state. When a gas of diatomic molecules is bombarded by energetic electrons, some of the molecules may be excited to higher electronic states, as occurs, for example, in the natural aurora; high-altitude nuclear explosions; and rocket-borne electron gun experiments. Such excitation can also occur when the gas absorbs light or other electromagnetic radiation. The excited states are unstable and naturally relax back to the ground state. Over various short time scales after the excitation (typically a fraction of a second, or sometimes longer than a second if the excited state is
metastable In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physics), motion and behavior through ...

), transitions occur from higher to lower electronic states and ultimately to the ground state, and in each transition results a
photon The photon ( el, φῶς, phōs, light) is a type of elementary particle In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be eleme ...

is emitted. This emission is known as
fluorescence light. Fluorescence is the emission of light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be visual perception, perceived by the human eye. Visible light is usually defi ...

. Successively higher electronic states are conventionally named $A$, $B$, $C$, etc. (but this convention is not always followed, and sometimes lower case letters and alphabetically out-of-sequence letters are used, as in the example given below). The excitation energy must be greater than or equal to the energy of the electronic state in order for the excitation to occur. In quantum theory, an electronic state of a diatomic molecule is represented by the
molecular term symbolIn molecular physics, the molecular term symbol is a shorthand expression of the group representation and angular momentum, angular momenta that characterize the state of a molecule, i.e. its electronic quantum state which is an eigenstate of the e ...
:$^ \Lambda \left(v\right)$ where $S$ is the total electronic spin quantum number, $\Lambda$ is the total electronic angular momentum quantum number along the internuclear axis, and $v$ is the vibrational quantum number. $\Lambda$ takes on values 0, 1, 2, ..., which are represented by the electronic state symbols $\Sigma$, $\Pi$, $\Delta$,.... For example, the following table lists the common electronic states (without vibrational quantum numbers) along with the energy of the lowest vibrational level ($v=0$) of diatomic nitrogen (N2), the most abundant gas in the Earth's atmosphere. In the table, the subscripts and superscripts after $\Lambda$ give additional quantum mechanical details about the electronic state. The aforementioned
fluorescence light. Fluorescence is the emission of light Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be visual perception, perceived by the human eye. Visible light is usually defi ...

occurs in distinct regions of the
electromagnetic spectrum The electromagnetic spectrum is the range of frequencies Frequency is the number of occurrences of a repeating event per unit of time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angula ...
, called " emission bands": each band corresponds to a particular transition from a higher electronic state and vibrational level to a lower electronic state and vibrational level (typically, many vibrational levels are involved in an excited gas of diatomic molecules). For example, N2 $A$-$X$ emission bands (a.k.a. Vegard-Kaplan bands) are present in the spectral range from 0.14 to 1.45 μm (micrometres). A given band can be spread out over several nanometers in electromagnetic wavelength space, owing to the various transitions that occur in the molecule's rotational quantum number, $J$. These are classified into distinct sub-band branches, depending on the change in $J$. The $R$ branch corresponds to $\Delta J = +1$, the $P$ branch to $\Delta J = -1$, and the $Q$ branch to $\Delta J = 0$. Bands are spread out even further by the limited
spectral resolutionThe spectral resolution of a spectrograph, or, more generally, of a frequency spectrum, is a measure of its ability to resolve features in the electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum ...
of the
spectrometer A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the ...

that is used to measure the
spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without steps, across a Continuum (theory), continuum. The word was first used scientifically in optics to describe the ...

. The spectral resolution depends on the instrument's
point spread function : central longitudinal (XZ) slice. The 3D acquired distribution arises from the convolution of the real light sources with the PSF. as imaged by a system with negative (top), zero (center), and positive (bottom) spherical aberration Spherical a ...
.

# Energy levels

The
molecular term symbolIn molecular physics, the molecular term symbol is a shorthand expression of the group representation and angular momentum, angular momenta that characterize the state of a molecule, i.e. its electronic quantum state which is an eigenstate of the e ...
is a shorthand expression of the angular momenta that characterize the electronic quantum states of a diatomic molecule, which are also
eigenstate In quantum physics, a quantum state is a mathematical entity that provides a probability distribution for the outcomes of each possible measurement ' Measurement is the number, numerical quantification (science), quantification of the variable an ...
s of the electronic molecular Hamiltonian. It is also convenient, and common, to represent a diatomic molecule as two-point masses connected by a massless spring. The energies involved in the various motions of the molecule can then be broken down into three categories: the translational, rotational, and vibrational energies. Concerning history, the first treatment of diatomic molecules with quantum mechanics was made by Lucy Mensing in 1926.

## Translational energies

The translational energy of the molecule is given by the
kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion (physics), motion. It is defined as the work (physics), work needed to accelerate a body of a given mass from rest to its stated velocity. Having gaine ...
expression: :$E_\text=\fracmv^2$ where $m$ is the mass of the molecule and $v$ is its velocity.

## Rotational energies

Classically, the kinetic energy of rotation is ::$E_\text = \frac \,$ :where ::$L \,$ is the
angular momentum In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum. It is an important quantity in physics because it is a conserved quantity—the total angular momentum of a close ...
::$I \,$ is the
moment of inertia The moment of inertia, otherwise known as the mass moment of inertia, angular mass, or most accurately, rotational inertia, of a rigid body is a quantity that determines the torque needed for a desired angular acceleration about a rotational ax ...

of the molecule For microscopic, atomic-level systems like a molecule, angular momentum can only have specific discrete values given by ::$L^2 = \ell\left(\ell+1\right) \hbar^2 \,$ :where $\ell$ is a non-negative integer and $\hbar$ is the
reduced Planck constant The Planck constant, or Planck's constant, is the quantum of electromagnetic action that relates a photon's energy to its frequency. The Planck constant multiplied by a photon's frequency is equal to a photon's energy. The Planck constant i ...
. Also, for a diatomic molecule the moment of inertia is ::$I = \mu r_^2 \,$ :where ::$\mu \,$ is the
reduced massIn physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physics), motion and behavior through Spac ...

of the molecule and ::$r_ \,$ is the average distance between the centers of the two atoms in the molecule. So, substituting the angular momentum and moment of inertia into Erot, the rotational energy levels of a diatomic molecule are given by: ::

## Vibrational energies

Another type of motion of a diatomic molecule is for each atom to oscillate—or —along the line connecting the two atoms. The vibrational energy is approximately that of a
quantum harmonic oscillator The quantum harmonic oscillator is the quantum-mechanical analog of the classical harmonic oscillator. Because an arbitrary smooth potential can usually be approximated as a harmonic potential at the vicinity of a stable equilibrium point, ...
: ::$E_\text = \left\left(n+\frac \right\right)\hbar \omega \ \ \ \ \ n=0,1,2,.... \,$ :where ::$n$ is an integer ::$\hbar$ is the
reduced Planck constant The Planck constant, or Planck's constant, is the quantum of electromagnetic action that relates a photon's energy to its frequency. The Planck constant multiplied by a photon's frequency is equal to a photon's energy. The Planck constant i ...
and ::$\omega$ is the
angular frequency Angular frequency ''ω'' (in radians per second), is larger than frequency ''ν'' (in cycles per second, also called Hertz, Hz), by a factor of . This figure uses the symbol ''ν'', rather than ''f'' to denote frequency. In [ hysics, angular freque ...
of the vibration.

## Comparison between rotational and vibrational energy spacings

The spacing, and the energy of a typical spectroscopic transition, between vibrational energy levels is about 100 times greater than that of a typical transition between rotational energy levels.

# Hund's cases

The good quantum numbers for a diatomic molecule, as well as good approximations of rotational energy levels, can be obtained by modeling the molecule using
Hund's cases In rotational-vibrational and electronic spectroscopy of diatomic molecules, Friedrich Hund, Hund's coupling cases are idealized descriptions of rotational states in which specific terms in the molecular Hamiltonian (quantum mechanics), Hamiltonian ...
.

# Mnemonics

The mnemonics ''BrINClHOF'', pronounced "Brinklehof", ''HONClBrIF'', pronounced "Honkelbrif", and ''HOFBrINCl'', pronounced "Hofbrinkle", have been coined to aid recall of the list of diatomic elements. Another method, for English-speakers, is the sentence: "''Never Have Fear of Ice Cold Beer''" as a representation of Nitrogen, Hydrogen, Fluorine, Oxygen, Iodine, Chlorine, Bromine.

* Symmetry of diatomic molecules * AXE method * Octatomic element *
Covalent bond A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they sh ...
*
Industrial gas Industrial gases are the gaseous materials that are manufactured for use in industry. The principal gases provided are nitrogen Nitrogen is the chemical element with the Symbol (chemistry), symbol N and atomic number 7. It was first disco ...

* * * *