Halogen

Group of chemical elements

This article is about the chemical series. For other uses, see Halogen (disambiguation).

Halogens

| Hydrogen |  | Helium

|
|

Lithium | Beryllium |  | Boron | Carbon | Nitrogen | Oxygen | Fluorine | Neon
Sodium | Magnesium |  | Aluminium | Silicon | Phosphorus | Sulfur | Chlorine | Argon
Potassium | Calcium |  | Scandium | Titanium | Vanadium | Chromium | Manganese | Iron | Cobalt | Nickel | Copper | Zinc | Gallium | Germanium | Arsenic | Selenium | Bromine | Krypton
Rubidium | Strontium |  |  | Yttrium | Zirconium | Niobium | Molybdenum | Technetium | Ruthenium | Rhodium | Palladium | Silver | Cadmium | Indium | Tin | Antimony | Tellurium | Iodine | Xenon
Caesium | Barium | Lanthanum | Cerium | Praseodymium | Neodymium | Promethium | Samarium | Europium | Gadolinium | Terbium | Dysprosium | Holmium | Erbium | Thulium | Ytterbium | Lutetium | Hafnium | Tantalum | Tungsten | Rhenium | Osmium | Iridium | Platinum | Gold | Mercury (element) | Thallium | Lead | Bismuth | Polonium | Astatine | Radon
Francium | Radium | Actinium | Thorium | Protactinium | Uranium | Neptunium | Plutonium | Americium | Curium | Berkelium | Californium | Einsteinium | Fermium | Mendelevium | Nobelium | Lawrencium | Rutherfordium | Dubnium | Seaborgium | Bohrium | Hassium | Meitnerium | Darmstadtium | Roentgenium | Copernicium | Nihonium | Flerovium | Moscovium | Livermorium | Tennessine | Oganesson

chalcogens ←    → noble gases

| IUPAC group number | 17

|

Name by element | fluorine group
Trivial name | halogens

CAS group number
(US, pattern A-B-A)

| VIIA

old IUPAC number
(Europe, pattern A-B)

| VIIB
↓ Period

2 |

Fluorine (F)
9 Halogen
3 |

Chlorine (Cl)
17 Halogen
4 |

Bromine (Br)
35 Halogen
5 |

Iodine (I)
53 Halogen
6 | Astatine (At)
85 Halogen
7 | Tennessine (Ts)
117 Halogen

* * *

Legend

| primordial element

element from decay
Synthetic

The halogens (/ˈhælədʒən, ˈheɪ-, -loʊ-, -ˌdʒɛn/[1][2][3]) are a group in the periodic table consisting of six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and the radioactive elements astatine (At) and tennessine (Ts), though some authors[4] would exclude tennessine as its chemistry is unknown and is theoretically expected to be more like that of gallium. In the modern IUPAC nomenclature, this group is known as group 17.[5]

The word "halogen" means "salt former" or "salt maker". When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide, and potassium iodide.[6]

The group of halogens is the only periodic table group that contains elements in three of the main states of matter at standard temperature and pressure, though not far above room temperature the same becomes true of groups 1 and 15, assuming white phosphorus is taken as the standard state.[n 1] All of the halogens form acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts. The middle halogens—chlorine, bromine, and iodine—are often used as disinfectants. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be toxic.

## History

[edit]

The fluorine mineral fluorspar was known as early as 1529. It is believed to be found in the foot bones of early dinosaurs.[citation needed] Early chemists realized that fluorine compounds contain an undiscovered element, but were unable to isolate it. In 1869, George Gore, an English chemist, ran a current of electricity through hydrofluoric acid and probably produced fluorine, but he was unable to prove his results at the time.[7] In 1886, Henri Moissan, a chemist in Paris, performed electrolysis on potassium bifluoride dissolved in anhydrous hydrogen fluoride, and successfully isolated fluorine.[8]

Hydrochloric acid was known to alchemists and early chemists. However, elemental chlorine was not produced until 1774, when Carl Wilhelm Scheele heated hydrochloric acid with manganese dioxide. Scheele called the element "dephlogisticated muriatic acid", which is how chlorine was known for 33 years. In 1807, Humphry Davy investigated chlorine and discovered that it is an actual element. Chlorine gas was used as a poisonous gas during World War I. It displaced oxygen in contaminated areas and replaced common oxygenated air with the toxic chlorine gas. The gas would burn human tissue externally and internally, especially the lungs, making breathing difficult or impossible depending on the level of contamination.[8]

Bromine was discovered in the 1820s by Antoine Jérôme Balard. Balard discovered bromine by passing chlorine gas through a sample of brine. He originally proposed the name muride for the new element, but the French Academy changed the element's name to bromine.[8]

Iodine was discovered by Bernard Courtois, who was using seaweed ash as part of a process for saltpeter manufacture. Courtois typically boiled the seaweed ash with water to generate potassium chloride. However, in 1811, Courtois added sulfuric acid to his process and found that his process produced purple fumes that condensed into black crystals. Suspecting that these crystals were a new element, Courtois sent samples to other chemists for investigation. Iodine was proven to be a new element by Joseph Gay-Lussac.[8]

In 1931, Fred Allison claimed to have discovered element 85 with a magneto-optical machine, and named the element Alabamine, but was mistaken. In 1937, Rajendralal De claimed to have discovered element 85 in minerals, and called the element dakine, but he was also mistaken. An attempt at discovering element 85 in 1939 by Horia Hulubei and Yvette Cauchois via spectroscopy was also unsuccessful, as was an attempt in the same year by Walter Minder, who discovered an iodine-like element resulting from beta decay of polonium. Element 85, now named astatine, was produced successfully in 1940 by Dale R. Corson, K.R. Mackenzie, and Emilio G. Segrè, who bombarded bismuth with alpha particles.[8]

In 2010, a team led by nuclear physicist Yuri Oganessian involving scientists from the JINR, Oak Ridge National Laboratory, Lawrence Livermore National Laboratory, and Vanderbilt University successfully bombarded berkelium-249 atoms with calcium-48 atoms to make tennessine.[9]

### Etymology

[edit]

In 1811, the German chemist Johann Schweigger proposed that the name "halogen" – meaning "salt producer", from αλς [hals] "salt" and γενειν [genein] "to beget" – replace the name "chlorine", which had been proposed by the English chemist Humphry Davy.[10] Davy's name for the element prevailed.[11] However, in 1826, the Swedish chemist Baron Jöns Jacob Berzelius proposed the term "halogen" for the elements fluorine, chlorine, and iodine, which produce a sea-salt-like substance when they form a compound with an alkaline metal.[12][13]

The English names of these elements all have the ending -ine. Fluorine's name comes from the Latin word fluere, meaning "to flow", because it was derived from the mineral fluorite, which was used as a flux in metalworking. Chlorine's name comes from the Greek word chloros, meaning "greenish-yellow". Bromine's name comes from the Greek word bromos, meaning "stench". Iodine's name comes from the Greek word iodes, meaning "violet". Astatine's name comes from the Greek word astatos, meaning "unstable".[8] Tennessine is named after the US state of Tennessee, where it was synthesized.

## Characteristics

[edit]

### Chemical

[edit]

The halogens fluorine, chlorine, bromine, and iodine are nonmetals; the chemical properties of astatine and tennessine, two heaviest group 17 members, have not been conclusively investigated. The halogens show trends in chemical bond energy moving from top to bottom of the periodic table column with fluorine deviating slightly. It follows a trend in having the highest bond energy in compounds with other atoms, but it has very weak bonds within the diatomic F2 molecule. This means that further down group 17 in the periodic table, the reactivity of elements decreases because of the increasing size of the atoms.[14]

Halogen bond energies (kJ/mol)[15] X  | X2 | HX  | BX3 | AlX3 | CX4

|
|
|
|
|

F  | 159 | 574 | 645 | 582 | 456
Cl  | 243  | 428  | 444  | 427  | 327
Br  | 193  | 363  | 368  | 360  | 272
I  | 151  | 294  | 272  | 285  | 239

Halogens are highly reactive, and as such can be harmful or lethal to biological organisms in sufficient quantities. This high reactivity is due to the high electronegativity of the atoms due to their high effective nuclear charge. Because the halogens have seven valence electrons in their outermost energy level, they can gain an electron by reacting with atoms of other elements to satisfy the octet rule. Fluorine is the most reactive of all elements; it is the only element more electronegative than oxygen, it attacks otherwise-inert materials such as glass, and it forms compounds with the usually inert noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that, if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4). Thus, fluorine must be handled with substances such as Teflon (which is itself an organofluorine compound), extremely dry glass, or metals such as copper or steel, which form a protective layer of fluoride on their surface.

The high reactivity of fluorine allows some of the strongest bonds possible, especially to carbon. For example, Teflon is fluorine bonded with carbon and is extremely resistant to thermal and chemical attacks and has a high melting point.

#### Molecules

[edit]

##### Diatomic halogen molecules

[edit]

The stable halogens form homonuclear diatomic molecules. Due to relatively weak intermolecular forces, chlorine and fluorine form part of the group known as "elemental gases".

halogen | molecule | structure | model | d(X−X) / pm
(gas phase) | d(X−X) / pm
(solid phase)

|
|
|
|
|

fluorine | F2 |  |  | 143 | 149
chlorine | Cl2 |  |  | 199 | 198
bromine | Br2 |  |  | 228 | 227
iodine | I2 |  |  | 266 | 272

The elements become less reactive and have higher melting points as the atomic number increases. The higher melting points are caused by stronger London dispersion forces resulting from more electrons.

#### Compounds

[edit]

##### Hydrogen halides

[edit]

Main article: Hydrogen halides

All of the halogens have been observed to react with hydrogen to form hydrogen halides. For fluorine, chlorine, and bromine, this reaction is in the form of:

H2 \+ X2 → 2HX

However, hydrogen iodide and hydrogen astatide can split back into their constituent elements.[16]

The hydrogen-halogen reactions get gradually less reactive toward the heavier halogens. A fluorine-hydrogen reaction is explosive even when it is dark and cold. A chlorine-hydrogen reaction is also explosive, but only in the presence of light and heat. A bromine-hydrogen reaction is even less explosive; it is explosive only when exposed to flames. Iodine and astatine only partially react with hydrogen, forming equilibria.[16]

All halogens form binary compounds with hydrogen known as the hydrogen halides: hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (HI), and hydrogen astatide (HAt). All of these compounds form acids when mixed with water. Hydrogen fluoride is the only hydrogen halide that forms hydrogen bonds. Hydrochloric acid, hydrobromic acid, hydroiodic acid, and hydroastatic acid are all strong acids, but hydrofluoric acid is a weak acid.[17]

All of the hydrogen halides are irritants. Hydrogen fluoride and hydrogen chloride are highly acidic. Hydrogen fluoride is used as an industrial chemical, and is highly toxic, causing pulmonary edema and damaging cells.[18] Hydrogen chloride is also a dangerous chemical. Breathing in gas with more than fifty parts per million of hydrogen chloride can cause death in humans.[19] Hydrogen bromide is even more toxic and irritating than hydrogen chloride. Breathing in gas with more than thirty parts per million of hydrogen bromide can be lethal to humans.[20] Hydrogen iodide, like other hydrogen halides, is toxic.[21]

##### Metal halides

[edit]

Main article: Metal halides

All the halogens are known to react with sodium to form sodium fluoride, sodium chloride, sodium bromide, sodium iodide, and sodium astatide. Heated sodium's reaction with halogens produces bright-orange flames. Sodium's reaction with chlorine is in the form of:

2Na + Cl2 → 2NaCl[16]

Iron reacts with fluorine, chlorine, and bromine to form iron(III) halides. These reactions are in the form of:

2Fe + 3X2 → 2FeX3[16]

However, when iron reacts with iodine, it forms only iron(II) iodide.

Fe + I2 → FeI2

Iron wool can react rapidly with fluorine to form the white compound iron(III) fluoride even in cold temperatures. When chlorine comes into contact with a heated iron, they react to form the black iron(III) chloride. However, if the reaction conditions are moist, this reaction will instead result in a reddish-brown product. Iron can also react with bromine to form iron(III) bromide. This compound is reddish-brown in dry conditions. Iron's reaction with bromine is less reactive than its reaction with fluorine or chlorine. A hot iron can also react with iodine, but it forms iron(II) iodide. This compound may be gray, but the reaction is always contaminated with excess iodine, so it is not known for sure. Iron's reaction with iodine is less vigorous than its reaction with the lighter halogens.[16]

##### Interhalogen compounds

[edit]

Main article: Interhalogen

Interhalogen compounds are in the form of XYn where X and Y are halogens and n is one, three, five, or seven. Interhalogen compounds contain at most two different halogens. Large interhalogens, such as ClF3 can be produced by a reaction of a pure halogen with a smaller interhalogen such as ClF. All interhalogens except IF7 can be produced by directly combining pure halogens in various conditions.[22]

Interhalogens are typically more reactive than all diatomic halogen molecules except F2 because interhalogen bonds are weaker. However, the chemical properties of interhalogens are still roughly the same as those of diatomic halogens. Many interhalogens consist of one or more atoms of fluorine bonding to a heavier halogen. Chlorine and bromine can bond with up to five fluorine atoms, and iodine can bond with up to seven fluorine atoms. Most interhalogen compounds are covalent gases. However, some interhalogens are liquids, such as BrF3, and many iodine-containing interhalogens are solids.[22]

##### Organohalogen compounds

[edit]

Many synthetic organic compounds such as plastic polymers, and a few natural ones, contain halogen atoms; these are known as halogenated compounds or organic halides. Chlorine is by far the most abundant of the halogens in seawater, and the only one needed in relatively large amounts (as chloride ions) by humans. For example, chloride ions play a key role in brain function by mediating the action of the inhibitory transmitter GABA and are also used by the body to produce stomach acid. Iodine is needed in trace amounts for the production of thyroid hormones such as thyroxine. Organohalogens are also synthesized through the nucleophilic abstraction reaction.[23]

##### Polyhalogenated compounds

[edit]

Polyhalogenated compounds are industrially created compounds substituted with multiple halogens. Many of them are very toxic and bioaccumulate in humans, and have a very wide application range. They include PCBs, PBDEs, and perfluorinated compounds (PFCs), as well as numerous other compounds.

#### Reactions

[edit]

##### Reactions with water

[edit]

Fluorine reacts vigorously with water to produce oxygen (O2) and hydrogen fluoride (HF):[24]

2 F2(g) + 2 H2O(l) → O2(g) + 4 HF(aq)

Chlorine has maximum solubility of ca. 7.1 g Cl2 per kg of water at ambient temperature (21 °C).[25] Dissolved chlorine reacts to form hydrochloric acid (HCl) and hypochlorous acid, a solution that can be used as a disinfectant or bleach:

Cl2(g) + H2O(l) → HCl(aq) + HClO(aq)

Bromine has a solubility of 3.41 g per 100 g of water,[26] but it slowly reacts to form hydrogen bromide (HBr) and hypobromous acid (HBrO):

Br2(g) + H2O(l) → HBr(aq) + HBrO(aq)

Iodine, however, is minimally soluble in water (0.03 g/100 g water at 20 °C) and does not react with it.[27] However, iodine will form an aqueous solution in the presence of iodide ion, such as by addition of potassium iodide (KI), because the triiodide ion is formed.

### Physical and atomic

[edit]

The table below is a summary of the key physical and atomic properties of the halogens. Data marked with question marks are either uncertain or are estimations partially based on periodic trends rather than observations.

Halogen  | Standard atomic weight
(Da)[n 2][29] | Melting point
(K)  | Melting point
(°C)  | Boiling point
(K)[30] | Boiling point
(°C)[30] | Density
(g/cm3 at 25 °C)  | Electronegativity
(Pauling)  | First ionization energy
(kJ·mol−1) | Covalent radius
(pm)[31]

|
|
|
|
|
|
|
|
|

Fluorine | 18.9984032(5) | 53.53 | −219.62 | 85.03 | −188.12 | 0.0017 | 3.98 | 1681.0 | 71
Chlorine | [35.446; 35.457][n 3] | 171.6 | −101.5 | 239.11 | −34.04 | 0.0032 | 3.16 | 1251.2 | 99
Bromine | 79.904(1) | 265.8 | −7.3 | 332.0 | 58.8 | 3.1028 | 2.96 | 1139.9 | 114
Iodine | 126.90447(3) | 386.85 | 113.7 | 457.4 | 184.3 | 4.933 | 2.66 | 1008.4 | 133
Astatine | [210][n 4] | 575 | 302 | ? 610 | ? 337 | ? 6.2–6.5[32] | 2.2 | 899.0[33] | ? 145[34]
Tennessine | [294][n 4] | ? 623-823[35] | ? 350-550[35] | ? 883[35] | ? 610[35] | ? 7.1-7.3[35] | - | ? 743[36] | ? 157[35]
Z | Element | Electrons per shell

|
|

9 | fluorine | 2, 7
17 | chlorine | 2, 8, 7
35 | bromine | 2, 8, 18, 7
53 | iodine | 2, 8, 18, 18, 7
85 | astatine | 2, 8, 18, 32, 18, 7
117 | tennessine | 2, 8, 18, 32, 32, 18, 7 (predicted)[37]
Boiling or sublimation temperature dependence for halogens at various pressures. The vertical bar indicates the melting point Sublimation or boiling point (oC) of halogens at various pressures[38] Tmelt (оС)  | −100.7  | −7.3  | 112.9

|
|
|

log(P[Pa])  | mmHg  | Cl2 | Br2 | I2
2.12490302  | 1  | −118  | −48.7  | 38.7
2.82387302  | 5  | −106.7  | −32.8  | 62.2
3.12490302  | 10  | −101.6  | −25  | 73.2
3.42593302  | 20  | −93.3  | −16.8  | 84.7
3.72696301  | 40  | −84.5  | −8  | 97.5
3.90305427  | 60  | −79  | −0.6  | 105.4
4.12490302  | 100  | −71.7  | 9.3  | 116.5
4.42593302  | 200  | −60.2  | 24.3  | 137.3
4.72696301  | 400  | −47.3  | 41  | 159.8
5.00571661  | 760  | −33.8  | 58.2  | 183
log(P[Pa])  | atm  | Cl2 | Br2 | I2
5.00571661  | 1  | −33.8  | 58.2  | 183
5.30674661  | 2  | −16.9  | 78.8  |
5.70468662  | 5  | 10.3  | 110.3  |
6.00571661  | 10  | 35.6  | 139.8  |
6.30674661  | 20  | 65  | 174  |
6.48283787  | 30  | 84.8  | 197  |
6.6077766  | 40  | 101.6  | 215  |
6.70468662  | 50  | 115.2  | 230  |
6.78386786  | 60  | 127.1  | 243.5  |

#### Isotopes

[edit]

Fluorine has one stable and naturally occurring isotope, fluorine-19. However, there are trace amounts in nature of the radioactive isotope fluorine-23, which occurs via cluster decay of protactinium-231. A total of eighteen isotopes of fluorine have been discovered, with atomic masses ranging from 13 to 31.

Chlorine has two stable and naturally occurring isotopes, chlorine-35 and chlorine-37. However, there are trace amounts in nature of the isotope chlorine-36, which occurs via spallation of argon-36. A total of 24 isotopes of chlorine have been discovered, with atomic masses ranging from 28 to 51.[8]

There are two stable and naturally occurring isotopes of bromine, bromine-79 and bromine-81. A total of 33 isotopes of bromine have been discovered, with atomic masses ranging from 66 to 98.

There is one stable and naturally occurring isotope of iodine, iodine-127. However, there are trace amounts in nature of the radioactive isotope iodine-129, which occurs via spallation and from the radioactive decay of uranium in ores. Several other radioactive isotopes of iodine have also been created naturally via the decay of uranium. A total of 38 isotopes of iodine have been discovered, with atomic masses ranging from 108 to 145.[8]

There are no stable isotopes of astatine. However, there are four naturally occurring radioactive isotopes of astatine produced via radioactive decay of uranium, neptunium, and plutonium. These isotopes are astatine-215, astatine-217, astatine-218, and astatine-219. A total of 31 isotopes of astatine have been discovered, with atomic masses ranging from 191 to 227.[8]

There are no stable isotopes of tennessine. Tennessine has only two known synthetic radioisotopes, tennessine-293 and tennessine-294.

## Production

[edit]

From left to right: chlorine, bromine, and iodine at room temperature. Chlorine is a gas, bromine is a liquid, and iodine is a solid. Fluorine could not be included in the image due to its high reactivity, and astatine and tennessine due to their radioactivity.

Approximately six million metric tons of the fluorine mineral fluorite are produced each year. Four hundred-thousand metric tons of hydrofluoric acid are made each year. Fluorine gas is made from hydrofluoric acid produced as a by-product in phosphoric acid manufacture. Approximately 15,000 metric tons of fluorine gas are made per year.[8]

The mineral halite is the mineral that is most commonly mined for chlorine, but the minerals carnallite and sylvite are also mined for chlorine. Forty million metric tons of chlorine are produced each year by the electrolysis of brine.[8]

Approximately 450,000 metric tons of bromine are produced each year. Fifty percent of all bromine produced is produced in the United States, 35% in Israel, and most of the remainder in China. Historically, bromine was produced by adding sulfuric acid and bleaching powder to natural brine. However, in modern times, bromine is produced by electrolysis, a method invented by Herbert Dow. It is also possible to produce bromine by passing chlorine through seawater and then passing air through the seawater.[8]

In 2003, 22,000 metric tons of iodine were produced. Chile produces 40% of all iodine produced, Japan produces 30%, and smaller amounts are produced in Russia and the United States. Until the 1950s, iodine was extracted from kelp. However, in modern times, iodine is produced in other ways. One way that iodine is produced is by mixing sulfur dioxide with nitrate ores, which contain some iodates. Iodine is also extracted from natural gas fields.[8]

Even though astatine is naturally occurring, it is usually produced by bombarding bismuth with alpha particles.[8]

Tennessine is made by using a cyclotron, fusing berkelium-249 and calcium-48 to make tennessine-293 and tennessine-294.

## Applications

[edit]

### Disinfectants

[edit]

Both chlorine and bromine are used as disinfectants for drinking water, swimming pools, fresh wounds, spas, dishes, and surfaces. They kill bacteria and other potentially harmful microorganisms through a process known as sterilization. Their reactivity is also put to use in bleaching. Sodium hypochlorite, which is produced from chlorine, is the active ingredient of most fabric bleaches, and chlorine-derived bleaches are used in the production of some paper products.

### Lighting

[edit]

Halogen lamps are a type of incandescent lamp using a tungsten filament in bulbs that have small amounts of a halogen, such as iodine or bromine added. This enables the production of lamps that are much smaller than non-halogen incandescent lightbulbs at the same wattage. The gas reduces the thinning of the filament and blackening of the inside of the bulb resulting in a bulb that has a much greater life. Halogen lamps glow at a higher temperature (2800 to 3400 kelvin) with a whiter colour than other incandescent bulbs. However, this requires bulbs to be manufactured from fused quartz rather than silica glass to reduce breakage.[39]

### Drug components

[edit]

In drug discovery, the incorporation of halogen atoms into a lead drug candidate results in analogues that are usually more lipophilic and less water-soluble.[40] As a consequence, halogen atoms are used to improve penetration through lipid membranes and tissues. It follows that there is a tendency for some halogenated drugs to accumulate in adipose tissue.

The chemical reactivity of halogen atoms depends on both their point of attachment to the lead and the nature of the halogen. Aromatic halogen groups are far less reactive than aliphatic halogen groups, which can exhibit considerable chemical reactivity. For aliphatic carbon-halogen bonds, the C-F bond is the strongest and usually less chemically reactive than aliphatic C-H bonds. The other aliphatic-halogen bonds are weaker, their reactivity increasing down the periodic table. They are usually more chemically reactive than aliphatic C-H bonds. As a consequence, the most common halogen substitutions are the less reactive aromatic fluorine and chlorine groups.

## Biological role

[edit]

Fluoride anions are found in ivory, bones, teeth, blood, eggs, urine, and hair of organisms. Fluoride anions in very small amounts may be essential for humans.[41] There are 0.5 milligrams of fluorine per liter of human blood. Human bones contain 0.2 to 1.2% fluorine. Human tissue contains approximately 50 parts per billion of fluorine. A typical 70-kilogram human contains 3 to 6 grams of fluorine.[8]

Chloride anions are essential to a large number of species, humans included. The concentration of chlorine in the dry weight of cereals is 10 to 20 parts per million, while in potatoes the concentration of chloride is 0.5%. Plant growth is adversely affected by chloride levels in the soil falling below 2 parts per million. Human blood contains an average of 0.3% chlorine. Human bone typically contains 900 parts per million of chlorine. Human tissue contains approximately 0.2 to 0.5% chlorine. There is a total of 95 grams of chlorine in a typical 70-kilogram human.[8]

Some bromine in the form of the bromide anion is present in all organisms. A biological role for bromine in humans has not been proven, but some organisms contain organobromine compounds. Humans typically consume 1 to 20 milligrams of bromine per day. There are typically 5 parts per million of bromine in human blood, 7 parts per million of bromine in human bones, and 7 parts per million of bromine in human tissue. A typical 70-kilogram human contains 260 milligrams of bromine.[8]

Humans typically consume less than 100 micrograms of iodine per day. Iodine deficiency can cause intellectual disability. Organoiodine compounds occur in humans in some of the glands, especially the thyroid gland, as well as the stomach, epidermis, and immune system. Foods containing iodine include cod, oysters, shrimp, herring, lobsters, sunflower seeds, seaweed, and mushrooms. However, iodine is not known to have a biological role in plants. There are typically 0.06 milligrams per liter of iodine in human blood, 300 parts per billion of iodine in human bones, and 50 to 700 parts per billion of iodine in human tissue. There are 10 to 20 milligrams of iodine in a typical 70-kilogram human.[8]

Astatine, although very scarce, has been found in micrograms in the earth.[8] It has no known biological role because of its high radioactivity, extreme rarity, and has a half-life of just about 8 hours for the most stable isotope.

Tennessine is purely man-made and has no other roles in nature.

## Toxicity

[edit]

The halogens tend to decrease in toxicity towards the heavier halogens.[42]

Fluorine gas is extremely toxic; breathing in fluorine at a concentration of 25 parts per million is potentially lethal. Hydrofluoric acid is also toxic, being able to penetrate skin and cause highly painful burns. In addition, fluoride anions are toxic, but not as toxic as pure fluorine. Fluoride can be lethal in amounts of 5 to 10 grams. Prolonged consumption of fluoride above concentrations of 1.5 mg/L is associated with a risk of dental fluorosis, an aesthetic condition of the teeth.[43] At concentrations above 4 mg/L, there is an increased risk of developing skeletal fluorosis, a condition in which bone fractures become more common due to the hardening of bones. Current recommended levels in water fluoridation, a way to prevent dental caries, range from 0.7 to 1.2 mg/L to avoid the detrimental effects of fluoride while at the same time reaping the benefits.[44] People with levels between normal levels and those required for skeletal fluorosis tend to have symptoms similar to arthritis.[8]

Chlorine gas is highly toxic. Breathing in chlorine at a concentration of 3 parts per million can rapidly cause a toxic reaction. Breathing in chlorine at a concentration of 50 parts per million is highly dangerous. Breathing in chlorine at a concentration of 500 parts per million for a few minutes is lethal. In addition, breathing in chlorine gas is highly painful because of its corrosive properties. Hydrochloric acid is the acid of chlorine, while relatively nontoxic, it is highly corrosive and releases very irritating and toxic hydrogen chloride gas in open air.[42]

Pure bromine is somewhat toxic but less toxic than fluorine and chlorine. One hundred milligrams of bromine is lethal.[8] Bromide anions are also toxic, but less so than bromine. Bromide has a lethal dose of 30 grams.[8]

Iodine is somewhat toxic, being able to irritate the lungs and eyes, with a safety limit of 1 milligram per cubic meter. When taken orally, 3 grams of iodine can be lethal. Iodide anions are mostly nontoxic, but these can also be deadly if ingested in large amounts.[8]

Astatine is radioactive and thus highly dangerous, but it has not been produced in macroscopic quantities and hence it is most unlikely that its toxicity will be of much relevance to the average individual.[8]

Tennessine cannot be chemically investigated due to how short its half-life is, although its radioactivity would make it very dangerous.

## Superhalogen

[edit]

Main article: Superatom

Certain aluminium clusters have superatom properties. These aluminium clusters are generated as anions (Al−
n with n = 1, 2, 3, ... ) in helium gas and reacted with a gas containing iodine. When analyzed by mass spectrometry one main reaction product turns out to be Al
13I−
.[45] These clusters of 13 aluminium atoms with an extra electron added do not appear to react with oxygen when it is introduced in the same gas stream. Assuming each atom liberates its 3 valence electrons, this means 40 electrons are present, which is one of the magic numbers for sodium and implies that these numbers are a reflection of the noble gases.

Calculations show that the additional electron is located in the aluminium cluster at the location directly opposite from the iodine atom. The cluster must therefore have a higher electron affinity for the electron than iodine and therefore the aluminium cluster is called a superhalogen (i.e., the vertical electron detachment energies of the moieties that make up the negative ions are larger than those of any halogen atom).[46] The cluster component in the Al
13I−
ion is similar to an iodide ion or a bromide ion. The related Al
13I−
2 cluster is expected to behave chemically like the triiodide ion.[47][48]

## See also

[edit]

Look up halogen in Wiktionary, the free dictionary.

* Halogen bond
* Halogen addition reaction
* Halogen lamp
* Halogenation
* Interhalogen
* Pseudohalogen

## Notes

[edit]

1. ^ This could also be the case for group 12, although copernicium's melting and boiling points are still uncertain.
2. ^ The number given in parentheses refers to the measurement uncertainty. This uncertainty applies to the least significant figure(s) of the number prior to the parenthesized value (i.e., counting from rightmost digit to left). For instance, 1.00794(7) stands for 1.00794±0.00007, while 1.00794(72) stands for 1.00794±0.00072.[28]
3. ^ The average atomic weight of this element changes depending on the source of the chlorine, and the values in brackets are the upper and lower bounds.[29]
4. ^ a b The element does not have any stable nuclides, and the value in brackets indicates the mass number of the longest-lived isotope of the element.[29]

## References

[edit]

1. ^ Jones, Daniel (2017) [1917]. Peter Roach; James Hartmann; Jane Setter (eds.). English Pronouncing Dictionary. Cambridge: Cambridge University Press. ISBN 978-3-12-539683-8.
2. ^ "Halogen". Merriam-Webster.com Dictionary. Merriam-Webster.
3. ^ "Halogen". Dictionary.com Unabridged (Online). n.d.
4. ^ Fricke, Burkhard [2007.12.??] Superheavy elements a prediction of their chemical and physical properties PDF | "Element 117" | www.researchgate.net | Retrieved - 2023.08.13 (20:58:??) -- yyyy.mm.dd (hh:mm:ss)
5. ^ Union internationale de chimie pure et appliquée, ed. (2005). Nomenclature of inorganic chemistry: IUPAC Recommendations 2005. Cambridge: Royal Society of Chemistry. p. 51\. ISBN 978-0-85404-438-2.
6. ^ "Chemical properties of the halogens - Group 17 - the halogens - Edexcel - GCSE Combined Science Revision - Edexcel". BBC Bitesize. Retrieved 2022-03-21.
7. ^ Toon, Richard (2011-09-01). "The discovery of fluorine". RSC Education. Retrieved 2025-06-20.
8. ^ a b c d e f g h i j k l m n o p q r s t u v w x Emsley, John (2011). Nature's Building Blocks. OUP Oxford. ISBN 978-0199605637.
9. ^ Oganessian, Yu.Ts.; Abdullin, F.Sh.; Bailey, P.D.; Benker, D.E.; Bennett, M.E.; Dmitriev, S.N.; et al. (2010). "Synthesis of a new element with atomic number Z = 117". Physical Review Letters. 104 (14): 142502. Bibcode:2010PhRvL.104n2502O. doi:10.1103/PhysRevLett.104.142502. PMID 20481935. S2CID 3263480.Z+=+117&rft.volume=104&rft.issue=14&rft.pages=142502&rft.date=2010&rft_id=info:doi/10.1103/PhysRevLett.104.142502&rft_id=https://api.semanticscholar.org/CorpusID:3263480#id-name=S2CID&rft_id=info:pmid/20481935&rft_id=info:bibcode/2010PhRvL.104n2502O&rft.aulast=Oganessian&rft.aufirst=Yu.Ts.&rft.au=Abdullin,+F.Sh.&rft.au=Bailey,+P.D.&rft.au=Benker,+D.E.&rft.au=Bennett,+M.E.&rft.au=Dmitriev,+S.N.&rft.au=Ezold,+J.G.&rft.au=Hamilton,+J.H.&rft.au=Henderson,+R.A.&rft.au=Itkis,+M.G.&rft.au=Lobanov,+Yuri+V.&rft.au=Mezentsev,+A.N.&rft.au=Moody,+K.+J.&rft.au=Nelson,+S.L.&rft.au=Polyakov,+A.N.&rft.au=Porter,+C.E.&rft.au=Ramayya,+A.V.&rft.au=Riley,+F.D.&rft.au=Roberto,+J.B.&rft.au=Ryabinin,+M.+A.&rft.au=Rykaczewski,+K.P.&rft.au=Sagaidak,+R.N.&rft.au=Shaughnessy,+D.A.&rft.au=Shirokovsky,+I.V.&rft.au=Stoyer,+M.A.&rft.au=Subbotin,+V.G.&rft.au=Sudowe,+R.&rft.au=Sukhov,+A.M.&rft.au=Tsyganov,+Yu.S.&rft.au=Utyonkov,+Vladimir+K.&rft.au=Voinov,+A.A.&rft.au=Vostokin,+G.K.&rft.au=Wilk,+P.A.&rft_id=https://doi.org/10.1103%2FPhysRevLett.104.142502&rfr_id=info:sid/en.wikipedia.org:Halogen" class="Z3988">
10. ^ Schweigger, J.S.C. (1811). "Nachschreiben des Herausgebers, die neue Nomenclatur betreffend" [Postscript of the editor concerning the new nomenclature]. Journal für Chemie und Physik (in German). 3 (2): 249–255. On p. 251, Schweigger proposed the word "halogen": "Man sage dafür lieber mit richter Wortbildung Halogen (da schon in der Mineralogie durch Werner's Halit-Geschlecht dieses Wort nicht fremd ist) von αλς Salz und dem alten γενειν (dorisch γενεν) zeugen." (One should say instead, with proper morphology, "halogen" (this word is not strange since [it's] already in mineralogy via Werner's "halite" species) from αλς [als] "salt" and the old γενειν [genein] (Doric γενεν) "to beget".)
11. ^ Snelders, H. A. M. (1971). "J. S. C. Schweigger: His Romanticism and His Crystal Electrical Theory of Matter". Isis. 62 (3): 328–338\. doi:10.1086/350763. JSTOR 229946. S2CID 170337569.
12. ^ In 1826, Berzelius coined the terms Saltbildare (salt-formers) and Corpora Halogenia (salt-making substances) for the elements chlorine, iodine, and fluorine. See: Berzelius, Jacob (1826). "Årsberättelser om Framstegen i Physik och Chemie" [Annual Report on Progress in Physics and Chemistry]. Arsb. Vetensk. Framsteg (in Swedish). 6. Stockholm, Sweden: P.A. Norstedt & Söner: 187. From p. 187: "De förre af dessa, d. ä. de electronegativa, dela sig i tre klasser: 1) den första innehåller kroppar, som förenade med de electropositiva, omedelbart frambringa salter, hvilka jag derför kallar Saltbildare (Corpora Halogenia). Desse utgöras af chlor, iod och fluor *)." (The first of them [i.e., elements], the electronegative [ones], are divided into three classes: 1) The first includes substances which, [when] united with electropositive [elements], immediately produce salts, and which I therefore name "salt-formers" (salt-producing substances). These are chlorine, iodine, and fluorine *).)
13. ^ The word "halogen" appeared in English as early as 1832 (or earlier). See, for example: Berzelius, J.J. with A.D. Bache, trans., (1832) "An essay on chemical nomenclature, prefixed to the treatise on chemistry," The American Journal of Science and Arts, 22: 248–276 ; see, for example p. 263.
14. ^ Page 43, Edexcel International GCSE chemistry revision guide, Curtis 2011
15. ^ Greenwood & Earnshaw 1997, p. 804.
16. ^ a b c d e Jim Clark (2011). "Assorted reactions of the halogens". Retrieved February 27, 2013.
17. ^ Jim Clark (2002). "THE ACIDITY OF THE HYDROGEN HALIDES". Retrieved February 24, 2013.
18. ^ "Facts about hydrogen fluoride". 2005. Archived from the original on 2013-02-01. Retrieved 2017-10-28.
19. ^ "Hydrogen chloride". Retrieved February 24, 2013.
20. ^ "Hydrogen bromide". Retrieved February 24, 2013.
21. ^ "Poison Facts:Low Chemicals: Hydrogen Iodid". Retrieved 2015-04-12.
22. ^ a b Saxena, P. B (2007). Chemistry Of Interhalogen Compounds. Discovery Publishing House. ISBN 9788183562430. Retrieved February 27, 2013.
23. ^ Gribble, G. W (2009). Naturally Occurring Organohalogen Compounds - A Comprehensive Update. Springer. ISBN 9783211993224. Retrieved April 23, 2022.
24. ^ "The Oxidising Ability of the Group 7 Elements". Chemguide.co.uk. Retrieved 2011-12-29.
25. ^ "Solubility of chlorine in water". Resistoflex.com. Archived from the original on 2012-04-23. Retrieved 2011-12-29.
26. ^ "Properties of bromine". bromaid.org. Archived from the original on December 8, 2007.
27. ^ "Iodine MSDS". Hazard.com. 1998-04-21. Retrieved 2011-12-29.
28. ^ "Standard Uncertainty and Relative Standard Uncertainty". CODATA reference. National Institute of Standards and Technology. Retrieved 26 September 2011.
29. ^ a b c Wieser, Michael E.; Coplen, Tyler B. (2011). "Atomic weights of the elements 2009 (IUPAC Technical Report)" (PDF). Pure Appl. Chem. 83 (2): 359–396\. doi:10.1351/PAC-REP-10-09-14. S2CID 95898322. Retrieved 5 December 2012.
30. ^ a b Lide, D. R., ed. (2003). CRC Handbook of Chemistry and Physics (84th ed.). Boca Raton, FL: CRC Press.
31. ^ Slater, J. C. (1964). "Atomic Radii in Crystals". Journal of Chemical Physics. 41 (10): 3199–3205\. Bibcode:1964JChPh..41.3199S. doi:10.1063/1.1725697.
32. ^ Bonchev, Danail; Kamenska, Verginia (1981). "Predicting the properties of the 113–120 transactinide elements". The Journal of Physical Chemistry. 85 (9): 1177–86\. doi:10.1021/j150609a021.
33. ^ Rothe, S.; Andreyev, A. N.; Antalic, S.; Borschevsky, A.; Capponi, L.; Cocolios, T. E.; De Witte, H.; Eliav, E.; et al. (2013). "Measurement of the First Ionization Potential of Astatine by Laser Ionization Spectroscopy". Nature Communications. 4: 1–6\. Bibcode:2013NatCo...4.1835R. doi:10.1038/ncomms2819. PMC 3674244. PMID 23673620.
34. ^ "Get Facts About the Element Astatine". www.thoughtco.com. Retrieved November 12, 2021.
35. ^ a b c d e f "How Much Do You Know About the Element Tennessine?". www.thoughtco.com. Retrieved November 12, 2021.
36. ^ "WebElements Periodic Table » Tennessine » properties of free atoms". www.webelements.com. Retrieved November 12, 2021.
37. ^ Morss, Lester R.; Edelstein, Norman M.; Fuger, Jean (2011). Morss, Lester R; Edelstein, Norman M; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements. Dordrecht, The Netherlands: Springer Science+Business Media. Bibcode:2011tcot.book.....M. doi:10.1007/978-94-007-0211-0. ISBN 978-94-007-0210-3.
38. ^ "Краткий справочник физико-химических величин Равделя, Л.: Химия, 1974 г. – 200 стр. \\\ стр 67 табл. 24" (PDF).
39. ^ "The Halogen Lamp". Edison Tech Center. Retrieved 2014-09-05.
40. ^ Thomas, G. (2000). Medicinal Chemistry an Introduction. John Wiley & Sons, West Sussex, UK. ISBN 978-0-470-02597-0.
41. ^ Fawell, J. "Fluoride in Drinking-water" (PDF). World Health Organisation. Retrieved 10 March 2016.
42. ^ a b Gray, Theodore (2010). The Elements. Running Press. ISBN 9781579128951.
43. ^ Fawell, J.; Bailey, K.; Chilton, J.; Dahi, E.; Fewtrell, L.; Magara, Y. (2006). "Guidelines and standards" (PDF). Fluoride in Drinking-water. World Health Organization. pp. 37–9\. ISBN 978-92-4-156319-2.
44. ^ "CDC Statement on the 2006 National Research Council (NRC) Report on Fluoride in Drinking Water". Centers for Disease Control and Prevention. July 10, 2013. Archived from the original on January 9, 2014. Retrieved August 1, 2013.
45. ^ Bergeron, D. E.; Castleman, A. Welford; Morisato, Tsuguo; Khanna, Shiv N. (2004). "Formation of Al13I−: Evidence for the Superhalogen Character of Al13". Science. 304 (5667): 84–7\. Bibcode:2004Sci...304...84B. doi:10.1126/science.1093902. PMID 15066775. S2CID 26728239.
46. ^ Giri, Santanab; Behera, Swayamprabha; Jena, Puru (2014). "Superhalogens as Building Blocks of Halogen-Free Electrolytes in Lithium-Ion Batteries†". Angewandte Chemie. 126 (50): 14136. Bibcode:2014AngCh.12614136G. doi:10.1002/ange.201408648.
47. ^ Ball, Philip (16 April 2005). "A New Kind of Alchemy". New Scientist.
48. ^ Bergeron, D. E.; Roach, P. J.; Castleman, A. W.; Jones, N. O.; Khanna, S. N. (2005). "Al Cluster Superatoms as Halogens in Polyhalides and as Alkaline Earths in Iodide Salts". Science. 307 (5707): 231–5\. Bibcode:2005Sci...307..231B. doi:10.1126/science.1105820. PMID 15653497. S2CID 8003390.

## Bibliography

[edit]

* Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.

* v
* t
* e

Periodic table

Periodic table forms|

* Alternatives
* Extended periodic table

Sets of elements|

| By periodic table structure|

| Groups|

* 1 (Hydrogen and alkali metals)
* 2 (Alkaline earth metals)
* 3
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* 5
* 6
* 7
* 8
* 9
* 10
* 11
* 12
* 13 (Triels)
* 14 (Tetrels)
* 15 (Pnictogens)
* 16 (Chalcogens)
* 17 (Halogens)
* 18 (Noble gases)

|

Periods|

* 1
* 2
* 3
* 4
* 5
* 6
* 7
* 8+
* Aufbau
* Fricke
* Pyykkö

Blocks|

* Aufbau principle

By metallicity|

| Metals|

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|

Metalloids|

* Lists of metalloids by source
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Elements|

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|

Properties|

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Data pages|

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See also|

* IUPAC
* nomenclature
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* Category
* WikiProject

* v
* t
* e

Periodic table

|  | 1 | 2 |  | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18

|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|

1 | H |  | He
2 | Li | Be |  | B | C | N | O | F | Ne
3 | Na | Mg |  | Al | Si | P | S | Cl | Ar
4 | K | Ca |  | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr
5 | Rb | Sr |  | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe
6 | Cs | Ba | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn
7 | Fr | Ra | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Nh | Fl | Mc | Lv | Ts | Og

| s-block | f-block | d-block | p-block

|
|
|

* v
* t
* e

Halogens

|    |

Fluorine

Atomic Number: 9
Atomic Weight: 18.9984032
Melting Point: 53.63 K
Boiling Point: 85.03 K
Specific mass: 0.001696 g/cm3
Electronegativity: 3.98

Chlorine

Atomic Number: 17
Atomic Weight: 35.453
Melting Point: 172.31 K
Boiling Point: 239.11 K
Specific mass: 0.003214 g/cm3
Electronegativity: 3.16

Bromine

Atomic Number: 35
Atomic Weight: 79.904
Melting Point: 266.05 K
Boiling Point: 332.0 K
Specific mass: 3.122 g/cm3
Electronegativity: 2.96

Iodine

Atomic Number: 53
Atomic Weight: 126.90447
Melting Point: 386.65 K
Boiling Point: 475.4 K
Specific mass: 4.93 g/cm3
Electronegativity: 2.66

Astatine

Atomic Number: 85
Atomic Weight: [210]
Melting Point: 575.15 K
Boiling Point: 610 K
Specific mass: 7 g/cm3
Electronegativity: 2.2

Tennessine

Atomic Number: 117
Atomic Weight: [294]
Melting Point: ? 573–773 K
Boiling Point: ? 823 K
Specific mass: ? g/cm3
Electronegativity: ?

|
|
|
|
|
|

* v
* t
* e

Salts and covalent derivatives of the fluoride ion

| HF |  |  |  | ?HeF2

|
|
|
|

LiF | BeF2 | BF
BF3
B2F4
+BO3 | CF4
CxFy
+CO3 | NF3
FN3
N2F2

N2F4
NF2
?NF5

+NO3 | OF2
O2F2

O3F2
O4F2
?OF4 | F2 | Ne
NaF | MgF2 | AlF
AlF3 | SiF4 | P2F4
PF3
PF5
+PO4 | S2F2
SF2
S2F4
SF3
SF4
S2F10
SF6
+SO4 | ClF
ClF3
ClF5 | ?ArF2
?ArF4
KF | CaF
CaF2 |  | ScF3 | TiF2
TiF3
TiF4 | VF2
VF3
VF4
VF5 | CrF2
CrF3
CrF4
CrF5
?CrF6 | MnF2
MnF3
MnF4
?MnF5 | FeF2
FeF3
FeF4 | CoF2
CoF3
CoF4 | NiF2
NiF3
NiF4 | CuF
CuF2
?CuF3 | ZnF2 | GaF2
GaF3 | GeF2
GeF4 | AsF3
AsF5 | Se2F2
SeF4
SeF6
+SeO3 | BrF
BrF3
BrF5 | KrF2
?KrF4
?KrF6
RbF | SrF
SrF2 |  | YF3 | ZrF2
ZrF3
ZrF4 | NbF4
NbF5 | MoF4
MoF5
MoF6 | TcF4
TcF

TcF6 | RuF3
RuF

RuF5
RuF6 | RhF3
RhF4
RhF5
RhF6 | PdF2
Pd[PdF6]
PdF4
?PdF6 | Ag2F
AgF
AgF2
AgF3 | CdF2 | InF
InF3 | SnF2
SnF4 | SbF3
SbF5 | TeF4
?Te2F10
TeF6
+TeO3 | IF
IF3
IF5
IF7
+IO3 | XeF2
XeF4
XeF6
?XeF8
CsF | BaF2 |   | LuF3 | HfF4 | TaF5 | WF4
WF5
WF6 | ReF4
ReF5
ReF6
ReF7 | OsF4
OsF5
OsF6
?OsF

?OsF
8 | IrF2
IrF3
IrF4
IrF5
IrF6 | PtF2
Pt[PtF6]
PtF4
PtF5
PtF6 | AuF
AuF3
Au2F10
?AuF6
AuF5•F2 | Hg2F2
HgF2
?HgF4 | TlF
TlF3 | PbF2
PbF4 | BiF3
BiF5 | ?PoF2
PoF4
PoF6 | AtF
?AtF3
?AtF5 | RnF2
?RnF

?RnF

FrF  | RaF2 |   | LrF3 | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og
| ↓  |  |
| LaF3 | CeF3
CeF4 | PrF3
PrF4 | NdF2
NdF3
NdF4 | PmF3 | SmF
SmF2
SmF3 | EuF2
EuF3 | GdF3 | TbF3
TbF4 | DyF2
DyF3
DyF4 | HoF3 | ErF3 | TmF2
TmF3 | YbF2
YbF3
AcF3 | ThF2
ThF3
ThF4 | PaF4
PaF5 | UF3
UF4
UF5
UF6 | NpF3
NpF4
NpF5
NpF6 | PuF3
PuF4
PuF5
PuF6 | AmF2
AmF3
AmF4
?AmF6 | CmF3
CmF4
?CmF6 | BkF3
BkF
4 | CfF3
CfF4 | EsF3
EsF4
?EsF6 | Fm  | Md  | No

* v
* t
* e

Salts and covalent derivatives of the chloride ion

| HCl |  |  |  | He

|
|
|
|

LiCl | BeCl2 | B4Cl4
B12Cl12
BCl3
B2Cl4
+BO3 | C2Cl2
C2Cl4
C2Cl6
CCl4

+CO3 | NCl3
ClN3

+NO3 | ClxOy
Cl2O
Cl2O2
ClO
ClO2
Cl2O4
Cl2O6
Cl2O7
ClO4
+O | ClF
ClF3
ClF5 | Ne
NaCl | MgCl2 | AlCl
AlCl3 | Si5Cl12
Si2Cl6
SiCl4 | P2Cl4
PCl3
PCl5
+P | S2Cl2
SCl2
SCl4
+SO4 | Cl2 | Ar
KCl | CaCl
CaCl2 |  | ScCl3 | TiCl2
TiCl3
TiCl4 | VCl2
VCl3
VCl4
VCl5 | CrCl2
CrCl3
CrCl4 | MnCl2
MnCl3 | FeCl2
FeCl3 | CoCl2
CoCl3 | NiCl2 | CuCl
CuCl2 | ZnCl2 | GaCl
GaCl3 | GeCl2
GeCl4 | AsCl3
AsCl5
+As | Se2Cl2
SeCl2
SeCl4 | BrCl | Kr
RbCl | SrCl2 |  | YCl3 | ZrCl2
ZrCl3
ZrCl4 | NbCl3
NbCl4
NbCl5 | MoCl2
MoCl3
MoCl4
MoCl5
MoCl6 | TcCl3
TcCl4 | RuCl2
RuCl3
RuCl4 | RhCl3 | PdCl2 | AgCl | CdCl2 | InCl
InCl2
InCl3 | SnCl2
SnCl4 | SbCl3
SbCl5 | Te3Cl2
TeCl2
TeCl4 | ICl
ICl3 | XeCl
XeCl2
XeCl4
CsCl | BaCl2 | *  | LuCl3 | HfCl4 | TaCl3
TaCl4
TaCl5 | WCl2
WCl3
WCl4
WCl5
WCl6 | ReCl3
ReCl4
ReCl5
ReCl6 | OsCl2
OsCl3
OsCl4
OsCl5 | IrCl2
IrCl3
IrCl4 | PtCl2
PtCl4 | AuCl
(Au[AuCl4])2
AuCl3 | Hg2Cl2
HgCl2 | TlCl
TlCl3 | PbCl2
PbCl4 | BiCl3 | PoCl2
PoCl4 | AtCl | Rn
FrCl | RaCl2 | **  | LrCl3 | RfCl4 | DbCl5 | SgO2Cl2 | BhO3Cl | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og

*  | LaCl3 | CeCl3 | PrCl3 | NdCl2
NdCl3 | PmCl3 | SmCl2
SmCl3 | EuCl2
EuCl3 | GdCl3 | TbCl3 | DyCl2
DyCl3 | HoCl3 | ErCl3 | TmCl2
TmCl3 | YbCl2
YbCl3
**  | AcCl3 | ThCl3
ThCl4 | PaCl4
PaCl5 | UCl3
UCl4
UCl5
UCl6 | NpCl3
NpCl4 | PuCl3 | AmCl2
AmCl3 | CmCl3 | BkCl3 | CfCl3
CfCl2 | EsCl2
EsCl3 | FmCl2 | MdCl2 | NoCl2

* v
* t
* e

Salts and covalent derivatives of the bromide ion

| HBr |  |  |  | He

|
|
|
|

LiBr | BeBr2 | BBr3
+BO3 | CBr4
+C | NBr3
BrN3
NH4Br
NOBr
+N | Br2O
BrO2
Br2O3
Br2O5 | BrF
BrF3
BrF5 | Ne
NaBr | MgBr2 | AlBr
AlBr3 | SiBr4 | PBr3
PBr5
PBr7
+P | S2Br2
SBr2 | BrCl | Ar
KBr | CaBr2
|  | ScBr3 | TiBr2
TiBr3
TiBr4 | VBr2
VBr3 | CrBr2
CrBr3
CrBr4 | MnBr2 | FeBr2
FeBr3 | CoBr2 | NiBr2 | CuBr
CuBr2 | ZnBr2 | GaBr3 | GeBr2
GeBr4 | AsBr3
+As
+AsO3 | SeBr2
SeBr4 | Br2 | Kr
RbBr | SrBr2 |  | YBr3 | ZrBr2
ZrBr3
ZrBr4 | NbBr5 | MoBr2
MoBr3
MoBr4 | TcBr3
TcBr4 | RuBr3 | RhBr3 | PdBr2 | AgBr | CdBr2 | InBr
InBr3 | SnBr2
SnBr4 | SbBr3
+Sb
-Sb | Te2Br
TeBr4
+Te | IBr
IBr3 | XeBr2
CsBr | BaBr2 | *  | LuBr3 | HfBr4 | TaBr5 | WBr5
WBr6 | ReBr3 | OsBr3
OsBr4 | IrBr3
IrBr
4 | PtBr2
PtBr4 | AuBr
AuBr3 | Hg2Br2
HgBr2 | TlBr | PbBr2 | BiBr3 | PoBr2
PoBr4 | AtBr | Rn
FrBr | RaBr2 | **  | Lr  | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og

*  | LaBr3 | CeBr3 | PrBr3 | NdBr2
NdBr3 | PmBr3 | SmBr2
SmBr3 | EuBr2
EuBr3 | GdBr3 | TbBr3 | DyBr3 | HoBr3 | ErBr3 | TmBr2
TmBr3 | YbBr2
YbBr3
**  | AcBr3 | ThBr4 | PaBr4
PaBr5 | UBr4
UBr5 | NpBr3
NpBr4 | PuBr3 | AmBr2
AmBr3 | CmBr3 | BkBr3 | CfBr3 | EsBr2
EsBr3 | Fm  | Md  | No

* v
* t
* e

Salts and covalent derivatives of the iodide ion

| HI
+H |  |  |  | He

|
|
|
|

LiI | BeI2 | BI3
+BO3 | CI4
+C | NI3
NH4I
+N | I2O4
I2O5
I2O6
I4O9 | IF
IF3
IF5
IF7 | Ne
NaI | MgI2 | AlI
AlI3 | SiI4 | PI3
P2I4

PI5 | S2I2 | ICl
ICl3 | Ar
KI | CaI2 |  | ScI3 | TiI2
TiI3
TiI4 | VI2
VI3 | CrI2
CrI3
CrI4 | MnI2 | FeI2
FeI3 | CoI2 | NiI2
-Ni | CuI | ZnI2 | GaI
GaI3 | GeI2
GeI4
+Ge | AsI3
As2I4
+As | Se  | IBr
IBr3 | Kr
RbI
RbI3 | SrI2 |  | YI3 | ZrI2
ZrI3
ZrI4 | NbI4
NbI5 | MoI2
MoI3 | TcI3 | RuI3 | RhI3 | PdI2 | AgI | CdI2 | InI
InI3 | SnI2
SnI4 | SbI3
+Sb | TeI4
+Te | I−

3 | Xe
CsI
CsI3 | BaI2 |   | LuI3 | HfI3
HfI4 | TaI4
TaI5 | WI2
WI3
WI4 | ReI3
ReI
4 | OsI
OsI2
OsI3 | IrI3
IrI
4 | PtI2
PtI4 | AuI
AuI3 | Hg2I2
HgI2 | TlI
TlI3 | PbI2 | BiI3 | PoI2
PoI4 | AtI | Rn
Fr  | RaI2 |   | Lr  | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og
| ↓  |  |
| LaI2
LaI3 | CeI2
CeI3 | PrI2
PrI3 | NdI2
NdI3 | PmI3 | SmI2
SmI3 | EuI2
EuI3 | GdI2
GdI3 | TbI3 | DyI2
DyI
3 | HoI3 | ErI3 | TmI2
TmI3 | YbI2
YbI3
AcI3 | ThI2
ThI3
ThI4 | PaI4
PaI5 | UI3
UI4 | NpI3 | PuI3 | AmI2
AmI3 | CmI3 | BkI
3 | CfI

CfI
3 | EsI2
EsI3 | Fm  | Md  | No

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