Which Element Is a Member of the Halogen Family

Group of chemical elements

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 Silvery 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 (chemical element) Thallium Pb 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 grouping number 17 Name past element fluorine group Trivial name halogens CAS grouping number (United states of america, pattern A-B-A) VIIA old IUPAC number (Europe, design A-B) VIIB
↓ Period
2	Fluorine (F) ix Element of group vii
3	Chlorine (Cl) 17 Halogen
4	Bromine (Br) 35 Element of group vii
5	Iodine (I) 53 Halogen
vi	Astatine (At) 85 Halogen
7	Tennessine (Ts) 117 Halogen
Fable primordial element chemical element from decay Synthetic Diminutive number colour: black=solid, green=liquid, red=gas
v t e

The halogens (^{[1] [2] [iii]}) are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The artificially created element 117, tennessine (Ts), may also be a halogen. In the mod IUPAC classification, this group is known as group 17.

The name "halogen" means "salt quondam". When halogens react with metals, they produce a broad range of salts, including calcium fluoride, sodium chloride (common tabular array salt), silver bromide and potassium iodide.

The group of halogens is the only periodic table group that contains elements in three of the chief states of matter at standard temperature and pressure. All of the halogens class acids when bonded to hydrogen. Most halogens are typically produced from minerals or salts. The middle halogens—chlorine, bromine, and iodine—are often used every bit disinfectants. Organobromides are the most important class of flame retardants, while elemental halogens are dangerous and can be toxic.

History [edit]

The fluorine mineral fluorospar was known as early as 1529. Early chemists realized that fluorine compounds contain an undiscovered element, simply were unable to isolate information technology. In 1860, George Gore, an English language chemist, ran a current of electricity through hydrofluoric acrid and probably produced fluorine, but he was unable to prove his results at the time. In 1886, Henri Moissan, a chemist in Paris, performed electrolysis on potassium bifluoride dissolved in anhydrous hydrogen fluoride, and successfully isolated fluorine.^[four]

Hydrochloric acid was known to alchemists and early on chemists. However, elemental chlorine was non produced until 1774, when Carl Wilhelm Scheele heated muriatic 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 chemical element. Chlorine combined with hydrochloric acid, likewise as sulfuric acrid in certain instances created chlorine gas which was a poisonous gas during World War I. It displaced oxygen in contaminated areas and replaced common oxygenated air with the toxic chlorine gas. In which the gas would fire human tissue externally and internally, peculiarly the lungs making breathing hard or incommunicable depending on the level of contamination.^[4]

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, only the French Academy changed the element's name to bromine.^[4]

Iodine was discovered by Bernard Courtois, who was using seaweed ash as part of a procedure 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 blackness crystals. Suspecting that these crystals were a new chemical element, Courtois sent samples to other chemists for investigation. Iodine was proven to exist a new element by Joseph Gay-Lussac.^[4]

In 1931, Fred Allison claimed to take discovered element 85 with a magneto-optical motorcar, and named the element Alabamine, simply was mistaken. In 1937, Rajendralal De claimed to have discovered element 85 in minerals, and called the chemical element dakine, merely he was also mistaken. An endeavour at discovering element 85 in 1939 by Horia Hulubei and Yvette Cauchois via spectroscopy was as well unsuccessful, as was an attempt in the same twelvemonth by Walter Minder, who discovered an iodine-like chemical element resulting from beta decay of polonium. Element 85, now named astatine, was produced successfully in 1940 past Dale R. Corson, One thousand.R. Mackenzie, and Emilio Thousand. Segrè, who bombarded bismuth with alpha particles.^[iv]

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-294. As of 2021, information technology is the most contempo element to exist discovered.

Etymology [edit]

In 1811, the German pharmacist Johann Schweigger proposed that the proper noun "halogen" – meaning "salt producer", from αλς [als] "salt" and γενειν [genein] "to beget" – replace the name "chlorine", which had been proposed past the English chemist Humphry Davy.^[5] Davy's proper noun for the element prevailed.^[half-dozen] However, in 1826, the Swedish pharmacist Baron Jöns Jacob Berzelius proposed the term "halogen" for the elements fluorine, chlorine, and iodine, which produce a ocean-common salt-similar substance when they form a compound with an alkaline metal.^{[7] [viii]}

The names of the elements all accept the ending -ine. Fluorine's name comes from the Latin word fluere, meaning "to flow", considering it was derived from the mineral fluorite, which was used as a flux in metalworking. Chlorine's name comes from the Greek discussion chloros, meaning "light-green-yellowish". Bromine'southward proper noun comes from the Greek discussion bromos, meaning "stench". Iodine's name comes from the Greek word iodes, meaning "violet". Astatine'due south proper noun comes from the Greek give-and-take astatos, meaning "unstable".^[4] Tennessine is named after the US land of Tennessee.

Characteristics [edit]

Chemic [edit]

The halogens fluorine, chlorine, bromine, and iodine are nonmetals; the chemical properties of the two heaviest grouping 17 members accept not been conclusively investigated. The halogens testify trends in chemical bond energy moving from top to bottom of the periodic table column with fluorine deviating slightly. It follows a tendency in having the highest bond energy in compounds with other atoms, merely it has very weak bonds within the diatomic F₂ molecule. This ways that further downward grouping 17 in the periodic tabular array, the reactivity of elements decreases because of the increasing size of the atoms.^[9]

Halogen bond energies (kJ/mol)^[10]

X	X2	HX	BX3	AlX3	CXiv
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 every bit such can be harmful or lethal to biological organisms in sufficient quantities. This loftier reactivity is due to the loftier electronegativity of the atoms due to their high effective nuclear charge. Considering the halogens take seven valence electrons in their outermost free energy level, they can gain an electron by reacting with atoms of other elements to satisfy the octet rule. Fluorine is the nearly reactive of all elements; it is the only element more electronegative than oxygen, information technology attacks otherwise-inert materials such equally drinking glass, and it forms compounds with the commonly inert noble gases. Information technology is a corrosive and highly toxic gas. The reactivity of fluorine is such that, if used or stored in laboratory glassware, information technology can react with drinking glass in the presence of pocket-size amounts of h2o to grade silicon tetrafluoride (SiF_four). Thus, fluorine must be handled with substances such every bit Teflon (which is itself an organofluorine compound), extremely dry drinking 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 chemic attacks and has a loftier melting betoken.

Molecules [edit]

Diatomic halogen molecules [edit]

The halogens form homonuclear diatomic molecules (not proven for astatine). Due to relatively weak intermolecular forces, chlorine and fluorine course part of the group known as "elemental gases".

halogen	molecule	structure	model	d(X−Ten) / pm (gas phase)	d(Ten−X) / pm (solid phase)
fluorine	F2			143	149
chlorine	Cl2			199	198
bromine	Br2			228	227
iodine	Itwo			266	272

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

Compounds [edit]

Hydrogen halides [edit]

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

H₂ + X₂ → 2HX

However, hydrogen iodide and hydrogen astatide tin separate dorsum into their constituent elements.^[xi]

The hydrogen-halogen reactions become gradually less reactive toward the heavier halogens. A fluorine-hydrogen reaction is explosive even when information technology is dark and cold. A chlorine-hydrogen reaction is as well explosive, but just in the presence of light and heat. A bromine-hydrogen reaction is fifty-fifty less explosive; it is explosive only when exposed to flames. Iodine and astatine only partially react with hydrogen, forming equilibria.^[11]

All halogens form binary compounds with hydrogen known equally the hydrogen halides: hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (HI), and hydrogen astatide (Chapeau). All of these compounds class acids when mixed with h2o. Hydrogen fluoride is the merely 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 acrid.^[12]

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.^[xiii] Hydrogen chloride is also a unsafe chemic. Breathing in gas with more than than l parts per 1000000 of hydrogen chloride tin can cause expiry in humans.^[xiv] Hydrogen bromide is even more toxic and irritating than hydrogen chloride. Breathing in gas with more than than thirty parts per million of hydrogen bromide can be lethal to humans.^[15] Hydrogen iodide, like other hydrogen halides, is toxic.^[xvi]

Metal halides [edit]

All the halogens are known to react with sodium to grade 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 grade of:

2Na + Cl₂ → 2NaCl ^[xi]

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

2Fe + 3X_two → 2FeX₃ ^[11]

Nonetheless, when iron reacts with iodine, it forms just iron(II) iodide.

Atomic number 26+I₂→FeI₂

Iron wool can react speedily with fluorine to course the white compound iron(III) fluoride even in common cold temperatures. When chlorine comes into contact with a heated fe, they react to form the black iron (3) chloride. However, if the reaction weather are moist, this reaction volition instead result in a cherry-red-brown product. Fe can also react with bromine to class iron(3) bromide. This chemical compound is ruby-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 chemical compound may be gray, but the reaction is ever contaminated with excess iodine, so information technology is not known for sure. Iron's reaction with iodine is less vigorous than its reaction with the lighter halogens.^[11]

Interhalogen compounds [edit]

Interhalogen compounds are in the form of XY_n where X and Y are halogens and n is one, three, five, or 7. Interhalogen compounds comprise at most two dissimilar halogens. Large interhalogens, such as ClF_three tin 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.^[17]

Interhalogens are typically more than reactive than all diatomic element of group vii molecules except F₂ because interhalogen bonds are weaker. However, the chemic properties of interhalogens are still roughly the same as those of diatomic halogens. Many interhalogens consist of ane or more atoms of fluorine bonding to a heavier element of group vii. Chlorine can bail with upwards to 3 fluorine atoms, bromine can bond with upward to five fluorine atoms, and iodine can bond with upwards to seven fluorine atoms. Most interhalogen compounds are covalent gases. However, some interhalogens are liquids, such every bit BrF₃, and many iodine-containing interhalogens are solids.^[17]

Organohalogen compounds [edit]

Many synthetic organic compounds such as plastic polymers, and a few natural ones, comprise halogen atoms; these are known as halogenated compounds or organic halides. Chlorine is by far the well-nigh abundant of the halogens in seawater, and the just one needed in relatively large amounts (as chloride ions) by humans. For example, chloride ions play a fundamental office in brain function by mediating the activeness of the inhibitory transmitter GABA and are as well used past the body to produce stomach acrid. Iodine is needed in trace amounts for the production of thyroid hormones such as thyroxine. Organohalogens are as well synthesized through the nucleophilic abstraction reaction.

Polyhalogenated compounds [edit]

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

Reactions [edit]

Reactions with water [edit]

Fluorine reacts vigorously with water to produce oxygen (O_two) and hydrogen fluoride (HF):^[eighteen]

2 F_two(g) + 2 H_iiO(l) → O₂(g) + 4 HF(aq)

Chlorine has maximum solubility of ca. 7.1 grand Cl_ii per kg of water at ambience temperature (21 °C).^[19] Dissolved chlorine reacts to form hydrochloric acid (HCl) and hypochlorous acrid, a solution that tin be used as a disinfectant or bleach:

Cl_two(g) + H_iiO(fifty) → HCl(aq) + HClO(aq)

Bromine has a solubility of three.41 k per 100 g of h2o,^[twenty] but it slowly reacts to form hydrogen bromide (HBr) and hypobromous acid (HBrO):

Br_ii(g) + H₂O(fifty) → HBr(aq) + HBrO(aq)

Iodine, yet, is minimally soluble in water (0.03 chiliad/100 thousand water at 20 °C) and does not react with information technology.^[21] However, iodine volition class an aqueous solution in the presence of iodide ion, such as by add-on of potassium iodide (KI), because the triiodide ion is formed.

Physical and atomic [edit]

The table below is a summary of the primal 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.

Element of group vii	Standard atomic weight (u)[due north i] [23]	Melting point (Thou)	Melting bespeak (°C)	Boiling point (1000)[24]	Boiling point (°C)[24]	Density (g/cm3at 25 °C)	Electronegativity (Pauling)	Showtime ionization energy (kJ·mol−i)	Covalent radius (pm)[25]
Fluorine	18.9984032(five)	53.53	−219.62	85.03	−188.12	0.0017	3.98	1681.0	71
Chlorine	[35.446; 35.457][n 2]	171.6	−101.5	239.11	−34.04	0.0032	iii.16	1251.2	99
Bromine	79.904(1)	265.8	−vii.3	332.0	58.8	3.1028	two.96	1139.9	114
Iodine	126.90447(3)	386.85	113.vii	457.4	184.3	iv.933	2.66	1008.4	133
Astatine	[210][n 3]	575	302	? 610	? 337	? vi.2–six.5[26]	2.2	? 887.7	? 145[27]
Tennessine	[294][n 4]	? 623-823[28]	? 350-550[28]	? 883[28]	? 610[28]	? 7.one-7.3[28]	-	? 743[29]	? 157[28]

Z	Element	No. of electrons/beat
nine	fluorine	2, seven
17	chlorine	2, eight, 7
35	bromine	two, 8, xviii, 7
53	iodine	ii, 8, 18, eighteen, seven
85	astatine	2, eight, eighteen, 32, 18, 7
117	tennessine	ii, eight, eighteen, 32, 32, xviii, 7 (predicted) [30]

Isotopes [edit]

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

Chlorine has two stable and naturally occurring isotopes, chlorine-35 and chlorine-37. Withal, in that location 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.^[four]

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, at that place 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 diminutive masses ranging from 108 to 145.^[4]

There are no stable isotopes of astatine. However, at that place are four naturally occurring radioactive isotopes of astatine produced via radioactivity 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.^[four]

Tennessine has just 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 non be included in the image due to its high reactivity, and astatine and tennessine due to their radioactive decay.

Approximately 6 1000000 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 acrid produced as a by-product in phosphoric acrid industry. Approximately 15,000 metric tons of fluorine gas are made per year.^[4]

The mineral halite is the mineral that is most unremarkably mined for chlorine, simply the minerals carnallite and sylvite are also mined for chlorine. 40 million metric tons of chlorine are produced each year past the electrolysis of brine.^[4]

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 State of israel, and most of the remainder in China. Historically, bromine was produced by adding sulfuric acid and bleaching powder to natural brine. Yet, in modernistic times, bromine is produced by electrolysis, a method invented by Herbert Dow. Information technology is too possible to produce bromine by passing chlorine through seawater and then passing air through the seawater.^[iv]

In 2003, 22,000 metric tons of iodine were produced. Chile produces 40% of all iodine produced, Nippon produces thirty%, and smaller amounts are produced in Russia and the U.s.. Until the 1950s, iodine was extracted from kelp. Even so, in modern times, iodine is produced in other ways. 1 way that iodine is produced is by mixing sulfur dioxide with nitrate ores, which comprise some iodates. Iodine is likewise extracted from natural gas fields.^[4]

Even though astatine is naturally occurring, it is commonly produced by bombarding bismuth with alpha particles.^[4]

Tennessine is fabricated 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, pond pools, fresh wounds, spas, dishes, and surfaces. They kill leaner 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 textile bleaches, and chlorine-derived bleaches are used in the production of some paper products. Chlorine also reacts with sodium to create sodium chloride, which is table table salt.

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-element of group vii incandescent lightbulbs at the same wattage. The gas reduces the thinning of the filament and blackening of the within of the bulb resulting in a seedling that has a much greater life. Halogen lamps glow at a higher temperature (2800 to 3400 kelvins) with a whiter color than other incandescent bulbs. However, this requires bulbs to exist manufactured from fused quartz rather than silica glass to reduce breakage.^[31]

Drug components [edit]

In drug discovery, the incorporation of halogen atoms into a atomic number 82 drug candidate results in analogues that are usually more than lipophilic and less water-soluble.^[32] Equally a consequence, element of group vii atoms are used to improve penetration through lipid membranes and tissues. It follows that there is a trend for some halogenated drugs to accumulate in adipose tissue.

The chemic reactivity of halogen atoms depends on both their point of attachment to the pb and the nature of the halogen. Aromatic halogen groups are far less reactive than aliphatic halogen groups, which can exhibit considerable chemic 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 tabular array. They are ordinarily more chemically reactive than aliphatic C-H bonds. As a consequence, the nearly common element of group vii substitutions are the less reactive aromatic fluorine and chlorine groups.

Biological role [edit]

Fluoride anions are establish in ivory, basic, teeth, claret, eggs, urine, and pilus of organisms. Fluoride anions in very small-scale amounts may be essential for humans.^[33] 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 fifty parts per billion of fluorine. A typical 70-kilogram human contains three to half-dozen grams of fluorine.^[iv]

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 afflicted past chloride levels in the soil falling below 2 parts per meg. Man blood contains an average of 0.3% chlorine. Homo bone typically contains 900 parts per one thousand thousand of chlorine. Human tissue contains approximately 0.2 to 0.5% chlorine. There is a total of 95 grams of chlorine in a typical seventy-kilogram human.^[4]

Some bromine in the course of the bromide anion is present in all organisms. A biological role for bromine in humans has non been proven, simply some organisms incorporate organobromine compounds. Humans typically consume 1 to twenty milligrams of bromine per day. At that place are typically v parts per million of bromine in homo blood, 7 parts per million of bromine in human bones, and vii parts per 1000000 of bromine in human tissue. A typical lxx-kilogram human contains 260 milligrams of bromine.^[4]

Humans typically consume less than 100 micrograms of iodine per solar day. Iodine deficiency tin cause intellectual disability. Organoiodine compounds occur in humans in some of the glands, specially the thyroid gland, besides as the stomach, epidermis, and immune organisation. Foods containing iodine include cod, oysters, shrimp, herring, lobsters, sunflower seeds, seaweed, and mushrooms. Yet, iodine is not known to have a biological office in plants. There are typically 0.06 milligrams per liter of iodine in human blood, 300 parts per billion of iodine in homo bones, and 50 to 700 parts per billion of iodine in human being tissue. There are 10 to xx milligrams of iodine in a typical seventy-kilogram homo.^[iv]

Astatine, although very scarce, has been found in micrograms in the world.^[iv] It has no known biological role because of its loftier radioactivity, extreme rarity, and has a half-life of just virtually viii hours for the nigh 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.^[34]

Fluorine gas is extremely toxic; breathing in fluorine at a concentration of 25 parts per meg 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 non as toxic as pure fluorine. Fluoride can be lethal in amounts of five to 10 grams. Prolonged consumption of fluoride to a higher place concentrations of ane.v mg/L is associated with a hazard of dental fluorosis, an artful condition of the teeth.^[35] At concentrations above 4 mg/Fifty, there is an increased hazard of developing skeletal fluorosis, a condition in which os fractures go more mutual due to the hardening of basic. Electric current recommended levels in water fluoridation, a fashion to preclude dental caries, range from 0.7 to one.2 mg/50 to avoid the detrimental effects of fluoride while at the aforementioned fourth dimension reaping the benefits.^[36] People with levels between normal levels and those required for skeletal fluorosis tend to have symptoms like to arthritis.^[4]

Chlorine gas is highly toxic. Breathing in chlorine at a concentration of 3 parts per one thousand thousand tin rapidly cause a toxic reaction. Animate 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. Breathing in chlorine gas is highly painful.^[34]

Pure bromine is somewhat toxic but less toxic than fluorine and chlorine. One hundred milligrams of bromine is lethal.^[4] Bromide anions are also toxic, simply less then than bromine. Bromide has a lethal dose of 30 grams.^[four]

Iodine is somewhat toxic, being able to irritate the lungs and eyes, with a prophylactic limit of i milligram per cubic meter. When taken orally, 3 grams of iodine tin can be lethal. Iodide anions are generally nontoxic, but these can besides be deadly if ingested in large amounts.^[4]

Astatine is very radioactive and thus highly dangerous, but information technology has not been produced in macroscopic quantities and hence it is most unlikely that its toxicity volition exist of much relevance to the average individual.^[iv]

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

Superhalogen [edit]

Certain aluminium clusters have superatom properties. These aluminium clusters are generated every bit anions (Al ⁻
_northward with n = ane, 2, three, ... ) in helium gas and reacted with a gas containing iodine. When analyzed by mass spectrometry one main reaction product turns out to be Al
₁₃ I ⁻
.^[37] These clusters of 13 aluminium atoms with an actress electron added do non appear to react with oxygen when it is introduced in the same gas stream. Assuming each atom liberates its 3 valence electrons, this means xl electrons are present, which is ane of the magic numbers for sodium and implies that these numbers are a reflection of the noble gases.

Calculations testify that the additional electron is located in the aluminium cluster at the location directly opposite from the iodine atom. The cluster must therefore accept a college electron affinity for the electron than iodine and therefore the aluminium cluster is called a superhalogen (i.east., the vertical electron disengagement energies of the moieties that make up the negative ions are larger than those of any halogen atom).^[38] The cluster component in the Al
₁₃ I ⁻
ion is similar to an iodide ion or a bromide ion. The related Al
_xiii I ⁻
_ii cluster is expected to behave chemically like the triiodide ion.^{[39] [40]}

See also [edit]

Look upwards halogen in Wiktionary, the free dictionary.

• Halogen bond
• Element of group vii lamp
• Halogenation
• Interhalogen
• Pseudohalogen

Notes [edit]

1. ^ The number given in parentheses refers to the measurement dubiousness. 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 ane.00794 ±0.00007 , while 1.00794(72) stands for 1.00794 ±0.00072 .^[22]
2. ^ The average atomic weight of this chemical element changes depending on the source of the chlorine, and the values in brackets are the upper and lower premises.^[23]
3. ^ The element does not have whatever stable nuclides, and the value in brackets indicates the mass number of the longest-lived isotope of the element.^[23]
4. ^ 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.^[23]

References [edit]

1. ^ Jones, Daniel (2017) [1917]. Peter Roach; James Hartmann; Jane Setter (eds.). English Pronouncing Dictionary. Cambridge: Cambridge University Press. ISBN978-3-12-539683-8.
2. ^ "Halogen". Merriam-Webster Dictionary.
3. ^ "Halogen". Lexicon.com Unabridged. Dictionary.com.
4. ^ ^{a b c d e f g h i j k l m northward o p q r southward t u five w ten} Emsley, John (2011). Nature's Building Blocks. ISBN978-0199605637.
5. ^ Schweigger, J.S.C. (1811). "Nachschreiben des Herausgebers, die neue Nomenclatur betreffend" [Postscript of the editor apropos 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'south Halit-Geschlecht dieses Wort nicht fremd ist) von αλς Salz und dem alten γενειν (dorisch γενεν) zeugen." (1 should say instead, with proper morphology, "element of group vii" (this discussion is not strange since [it'south] already in mineralogy via Werner's "halite" species) from αλς [als] "salt" and the old γενειν [genein] (Doric γενεν) "to beget".)
6. ^ Snelders, H. A. Yard. (1971). "J. Southward. C. Schweigger: His Romanticism and His Crystal Electrical Theory of Thing". Isis. 62 (3): 328–338. doi:10.1086/350763. JSTOR 229946. S2CID 170337569.
7. ^ In 1826, Berzelius coined the terms Saltbildare (table salt-formers) and Corpora Halogenia (common salt-making substances) for the elements chlorine, iodine, and fluorine. See: Berzelius, Jacob (1826). Årsberättelser om Framstegen i Physik och Chemie [Almanac Study on Progress in Physics and Chemistry] (in Swedish). Vol. 6. Stockholm, Sweden: P.A. Norstedt & Söner. p. 187. From p. 187: "De förre af dessa, d. ä. de electronegativa, dela sig i tre klasser: i) 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 start includes substances which, [when] united with electropositive [elements], immediately produce salts, and which I therefore name "table salt-formers" (common salt-producing substances). These are chlorine, iodine, and fluorine *).)
8. ^ The word "halogen" appeared in English equally early every bit 1832 (or before). Come across, for example: Berzelius, J.J. with A.D. Bache, trans., (1832) "An essay on chemical nomenclature, prefixed to the treatise on chemical science," The American Journal of Scientific discipline and Arts, 22: 248–276 ; see, for case p. 263.
9. ^ Page 43, Edexcel International GCSE chemistry revision guide, Curtis 2011
10. ^ Greenwood & Earnshaw 1997, p. 804. sfn error: no target: CITEREFGreenwoodEarnshaw1997 (aid)
11. ^ ^{a b c d e} Jim Clark (2011). "Assorted reactions of the halogens". Retrieved Feb 27, 2013.
12. ^ Jim Clark (2002). "THE Acerbity OF THE HYDROGEN HALIDES". Retrieved February 24, 2013.
13. ^ "Facts about hydrogen fluoride". 2005. Archived from the original on 2013-02-01. Retrieved 2017-10-28 .
14. ^ "Hydrogen chloride". Retrieved February 24, 2013.
15. ^ "Hydrogen bromide". Retrieved February 24, 2013.
16. ^ "Poison Facts:Low Chemicals: Hydrogen Iodid". Retrieved 2015-04-12 .
17. ^ ^{a b} Saxena, P. B (2007). Chemical science Of Interhalogen Compounds. ISBN9788183562430 . Retrieved Feb 27, 2013.
18. ^ "The Oxidising Ability of the Group vii Elements". Chemguide.co.united kingdom. Retrieved 2011-12-29 .
19. ^ "Solubility of chlorine in h2o". Resistoflex.com. Retrieved 2011-12-29 .
20. ^ "Backdrop of bromine". bromaid.org. Archived from the original on Dec viii, 2007.
21. ^ "Iodine MSDS". Take chances.com. 1998-04-21. Retrieved 2011-12-29 .
22. ^ "Standard Uncertainty and Relative Standard Doubtfulness". CODATA reference. National Institute of Standards and Technology. Retrieved 26 September 2011.
23. ^ ^{a b c d} 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.
24. ^ ^{a b} Lide, D. R., ed. (2003). CRC Handbook of Chemistry and Physics (84th ed.). Boca Raton, FL: CRC Printing.
25. ^ 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.
26. ^ Bonchev, Danail; Kamenska, Verginia (1981). "Predicting the backdrop of the 113–120 transactinide elements". The Journal of Physical Chemical science. 85 (9): 1177–86. doi:10.1021/j150609a021.
27. ^ "Get Facts About the Element Astatine". www.thoughtco.com . Retrieved November 12, 2021.
28. ^ ^{a b c d e f} "How Much Do You lot Know About the Element Tennessine?website=www.thoughtco.com". Retrieved November 12, 2021.
29. ^ "WebElements Periodic Table » Tennessine » properties of free atoms". world wide web.webelements.com . Retrieved Nov 12, 2021.
30. ^
31. ^ "The Element of group vii Lamp". Edison Tech Center . Retrieved 2014-09-05 .
32. ^ Thomas, G. (2000). Medicinal Chemistry an Introduction. John Wiley & Sons, West Sussex, U.k.. ISBN978-0-470-02597-0.
33. ^ Fawell, J. "Fluoride in Drinking-water" (PDF). World Health System. Retrieved x March 2016.
34. ^ ^{a b} Gray, Theodore (2010). The Elements. ISBN9781579128951.
35. ^ 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. ISBN978-92-4-156319-2.
36. ^ "CDC Argument on the 2006 National Research Quango (NRC) Written report on Fluoride in Drinking H2o". Centers for Disease Control and Prevention. July 10, 2013. Archived from the original on January 9, 2014. Retrieved August 1, 2013.
37. ^ 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–vii. Bibcode:2004Sci...304...84B. doi:10.1126/science.1093902. PMID 15066775. S2CID 26728239.
38. ^ Giri, Santanab; Behera, Swayamprabha; Jena, Puru (2014). "Superhalogens as Building Blocks of Halogen-Free Electrolytes in Lithium-Ion Batteries†". Angewandte Chemie. 126 (50): 14136. doi:10.1002/ange.201408648.
39. ^ Brawl, Philip (16 Apr 2005). "A New Kind of Alchemy". New Scientist.
40. ^ 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/scientific discipline.1105820. PMID 15653497. S2CID 8003390.

Further reading [edit]

• Greenwood, Norman Due north.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN978-0-08-037941-8.

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Source: https://en.wikipedia.org/wiki/Halogen

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