FACTOID # 8: Bookworms: Vermont has the highest number of high school teachers per capita and third highest number of librarians per capita.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Francium" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Francium
87 radonfranciumradium
Cs

Fr

Uue
General
Name, Symbol, Number francium, Fr, 87
Chemical series alkali metals
Group, Period, Block 1, 7, s
Appearance metallic
Standard atomic weight (223) g·mol−1
Electron configuration [Rn] 7s1
Electrons per shell 2, 8, 18, 32, 18, 8, 1
Physical properties
Phase  ? solid
Density (near r.t.)  ? 1.87 g·cm−3
Melting point  ? 300 K
(27 °C, 80 °F)
Boiling point  ? 950 K
(? 677 °C, ? 1250 °F)
Heat of fusion ca. 2 kJ·mol−1
Heat of vaporization ca. 65 kJ·mol−1
Vapor pressure (extrapolated)
P(Pa) 1 10 100 1 k 10 k 100 k
at T(K) 404 454 519 608 738 946
Atomic properties
Crystal structure  ? cubic body centered
Oxidation states 1
(strongly basic oxide)
Electronegativity 0.7 (scale Pauling)
Ionization energies 1st: 380 kJ/mol
Miscellaneous
Magnetic ordering  ?
Electrical resistivity  ? 3 µΩ·m
Thermal conductivity (300 K)  ? 15 W·m−1·K−1
CAS registry number 7440-73-5
Selected isotopes
Main article: Isotopes of francium
iso NA half-life DM DE (MeV) DP
221Fr syn 4.8 min α 6.457 217At
222Fr syn 14.2 min β- 2.033 222Ra
223Fr syn 22.00 min β- 1.149 223Ra
α 5.430 219At
References

Francium (pronounced /ˈfrænsiəm/), formerly known as eka-caesium and actinium K,[1] is a chemical element that has the symbol Fr and atomic number 87. It has the lowest known electronegativity of all known elements, and is the second rarest naturally occurring element (after astatine). Francium is a highly radioactive metal that decays into astatine, radium, and radon. As an alkali metal, it has one valence electron. For other uses, see Radon (disambiguation). ... General Name, Symbol, Number radium, Ra, 88 Chemical series alkaline earth metals Group, Period, Block 2, 7, s Appearance silvery white metallic Standard atomic weight (226) g·mol−1 Electron configuration [Rn] 7s2 Electrons per shell 2, 8, 18, 32, 18, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Standard atomic weight 132. ... General Name, Symbol, Number ununennium, Uue, 119 Chemical series Presumably Alkali metals Group, Period, Block 1, 8, s Appearance unknown, probably colorless Atomic mass predicted, (316) g/mol Electron configuration [Uuo] 8s1 (a guess based upon cesium and francium) Electrons per shell 2, 8, 18, 32, 32, 18, 8, 1... Image File history File links Download high resolution version (900x270, 29 KB) Image by Daniel Mayer or GreatPatton and released under terms of the GNU FDL File links The following pages link to this file: Francium User:Femto/elements e10 ... This is a standard display of the periodic table of the elements. ... An extended periodic table was suggested by Glenn T. Seaborg in 1969. ... This is a list of chemical elements, sorted by name and color coded according to type of element. ... A table of chemical elements ordered by atomic number and color coded according to type of element. ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... The alkali metals are a series of elements comprising Group 1 (IUPAC style) of the periodic table: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... In the periodic table of the elements, a period is a horizontal row of the table. ... A block of the periodic table of elements is a set of adjacent groups. ... The alkali metals are a chemical series. ... A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements. ... The s-block of the periodic table of elements consists of the first two groups: the alkali metals and alkaline earth metals, plus hydrogen. ... Color is an important part of the visual arts. ... The atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units. ... Electron atomic and molecular orbitals In atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (, a crystal). ... For other uses, see Radon (disambiguation). ... For other uses, see Electron (disambiguation). ... Example of a sodium electron shell model An electron shell, also known as a main energy level, is a group of atomic orbitals with the same value of the principal quantum number n. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... For other uses, see Solid (disambiguation). ... For other uses, see Density (disambiguation). ... For other uses, see Room temperature (disambiguation). ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... For other uses, see Kelvin (disambiguation). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... For other uses, see Fahrenheit (disambiguation). ... Italic text This article is about the boiling point of liquids. ... For other uses, see Kelvin (disambiguation). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... For other uses, see Fahrenheit (disambiguation). ... Standard enthalpy change of fusion of period three. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... The standard enthalpy change of vaporization, ΔvHo, also (less correctly) known as the heat of vaporization is the energy required to transform a given quantity of a substance into a gas. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... Vapor pressure is the pressure of a vapor in equilibrium with its non-vapor phases. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The oxidation number of an element in a molecule or complex is the charge that it would have if all the ligands (basically, atoms that donate electrons) were removed along with the electron pairs that were shared with the central atom[1]. It means that the oxidation number is the... Acids and bases: Acid-base extraction Acid-base reaction Acid dissociation constant Acidity function Buffer solutions pH Proton affinity Self-ionization of water Acids: Lewis acids Mineral acids Organic acids Strong acids Superacids Weak acids Bases: Lewis bases Organic bases Strong bases Superbases Non-nucleophilic bases Weak bases edit In... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... The ionization energy (IE) of an atom or of a molecule is the energy required to strip it of an electron. ... Kilojoule per mole are an SI derived unit of energy per amount of material, where energy is measured in units of 1000 joules, and the amount of material is measured in mole units. ... For other senses of this word, see magnetism (disambiguation). ... // Headline text POOP!! Danny Hornsby (also known as Gnome) is a measure indicating how strongly a Gnome can opposes the flow of electric current. ... K value redirects here. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Francium (Fr) Has no stable isotopes. ... For other uses, see Isotope (disambiguation). ... Natural abundance refers to the prevalence of different isotopes of an element as found in nature. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. ... The decay energy is the energy released by a nuclear decay. ... The electronvolt (symbol eV) is a unit of energy. ... In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. ... A Synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. ... Alpha decay is a form of radioactive decay in which an atomic nucleus ejects an alpha particle and transforms into a nucleus with mass number 4 less and atomic number 2 less. ... General Name, Symbol, Number astatine, At, 85 Chemical series halogens Group, Period, Block 17, 6, p Appearance metallic (presumed) Standard atomic weight (210) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p5 Electrons per shell 2, 8, 18, 32, 18, 7 Physical properties Phase solid Melting point 575 K... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... General Name, Symbol, Number radium, Ra, 88 Chemical series alkaline earth metals Group, Period, Block 2, 7, s Appearance silvery white metallic Standard atomic weight (226) g·mol−1 Electron configuration [Rn] 7s2 Electrons per shell 2, 8, 18, 32, 18, 8, 2 Physical properties Phase solid Density (near r. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... The periodic table of the chemical elements A chemical element, or element, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. ... See also: List of elements by atomic number In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. ... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... The abundance of a chemical element measures how relatively common the element is, or how much of the element there is by comparison to all other elements. ... General Name, Symbol, Number astatine, At, 85 Chemical series halogens Group, Period, Block 17, 6, p Appearance metallic (presumed) Standard atomic weight (210) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p5 Electrons per shell 2, 8, 18, 32, 18, 7 Physical properties Phase solid Melting point 575 K... Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. ... General Name, Symbol, Number radium, Ra, 88 Chemical series alkaline earth metals Group, Period, Block 2, 7, s Appearance silvery white metallic Standard atomic weight (226) g·mol−1 Electron configuration [Rn] 7s2 Electrons per shell 2, 8, 18, 32, 18, 8, 2 Physical properties Phase solid Density (near r. ... For other uses, see Radon (disambiguation). ... The alkali metals are a series of elements comprising Group 1 (IUPAC style) of the periodic table: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). ... In chemistry, valence electrons are the electrons contained in the outermost, or valence, electron shell of an atom. ...


Marguerite Perey discovered francium in 1939. Francium was the last element discovered in nature, rather than synthesized.[2] Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and decays. Perhaps an ounce (30 g) exists at any given time throughout the Earth's crust; the other isotopes are entirely synthetic. The largest amount ever collected of any isotope was a cluster of 10,000 atoms (of francium-210) created as an ultracold gas at Stony Brook in 1997.[3] Marguerite Catherine Perey (1909 - 1975) was a French physicist. ... This article is about the physical universe. ... General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight 232. ... For other uses, see Isotope (disambiguation). ... This article is about Earth as a planet. ... Earth cutaway from core to exosphere. ... Ultracold atoms is a term used to describe atoms that are maintained at temperatures close to 0 kelvin (Absolute Zero), where their quantum-mechanical properties become important. ... The State University of New York at Stony Brook (SUNYSB), also known as Stony Brook University (SBU) is a public research university located in Stony Brook, New York (on the north side of Long Island, about 55 miles east of Manhattan, New York). ...

Contents

Characteristics

Francium is less stable than any other element lighter than nobelium, element 102:[3] its most stable isotope, francium-223, has a half-life of less than 22 minutes. By contrast, astatine, the next least stable element, has a maximum half-life of 8.5 hours.[4] All isotopes of francium decay into either astatine, radium, or radon.[4] General Name, Symbol, Number nobelium, No, 102 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (259) g/mol Electron configuration [Rn] 5f14 7s2 Electrons per shell 2, 8, 18, 32, 32, 8, 2 Physical properties Phase solid Melting... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ...


Francium is an alkali metal whose chemical properties most resemble those of cesium.[3] As a very heavy element with a single valence electron,[5] it therefore has the highest equivalent weight of any element.[3] Similarly, francium has the lowest electronegativity of all the known elements at 0.7 on the Pauling scale;[6] caesium has the second-lowest at 0.79.[7] Liquid francium—if such a substance were to be created—should have a surface tension of 0.05092 N/m at its melting point.[8] Francium coprecipitates with several caesium salts, such as caesium perchlorate, which results in small amounts of francium perchlorate. This coprecipitation can be used to isolate francium, by adapting the radiocaesium coprecipitation method of Glendenin and Nelson. It will additionally coprecipitate with many other caesium salts, including the iodate, the picrate, the tartrate (also rubidium tartrate), the chloroplatinate, and the silicotungstate. It also coprecipitates with silicotungstic acid, and with perchloric acid, without another alkali metal as a carrier, which provides other methods of separation.[9][10] Nearly all francium salts are water-soluble.[11] The alkali metals are a series of elements comprising Group 1 (IUPAC style) of the periodic table: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). ... General Name, Symbol, Number Caesium, Cs, 55 Series Alkali metals Group, Period, Block 1(IA), 6, s Density, Hardness 1879 kg/m3, 0. ... In chemistry, valence electrons are the electrons contained in the outermost, or valence, electron shell of an atom. ... Equivalent weight is the atomic weight of an element or radical divided by the valence it assumes in a chemical compound. ... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... Electronegativity is a measure of the attraction that an atom has for the bonding pair of electrons in a covalent bond. ... General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Standard atomic weight 132. ... Surface tension is an effect within the surface layer of a liquid that causes that layer to behave as an elastic sheet. ... For other uses, see Newton (disambiguation). ... This article is about the unit of length. ... In chemistry, coprecipitation (CPT) or co-precipitation is the carrying down by a precipitate of substances normally soluble under the conditions employed. ... For other uses, see Salt (disambiguation). ... Caesium perchlorate, CsClO4, is a perchlorate of caesium. ... An iodate is a salt of iodic acid. ... A picrate is a salt or an ester of picric acid (a 2,4,6-trinitrophenol). ... A tartrate is a salt or ester of the organic compound tartaric acid, a dicarboxylic acid. ... General Name, Symbol, Number rubidium, Rb, 37 Chemical series alkali metals Group, Period, Block 1, 5, s Appearance grey white Atomic mass 85. ... Tungstosilicic acid is the most commonly encountered heteropoly acid. ... Perchloric acid has the formula HClO4 and is a colorless liquid soluble in water. ... In chemistry, coprecipitation (CPT) or co-precipitation is the carrying down by a precipitate of substances normally soluble under the conditions employed. ... Solubility is a chemical property referring to the ability for a given substance, the solute, to dissolve in a solvent. ...


Applications

Due to its instability and rarity,[12][13][14][15][16] there are no commercial applications for francium. It has, however, been used for research purposes, both in the fields of biology and atomic structure. Its use as a potential diagnostic aid for various cancers has also been explored,[4] but this application has been deemed impractical.[14] Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek: βίος, bio, life; and λόγος, logos, knowledge), also referred to as the biological sciences, is the study of living organisms utilizing the scientific method. ... Properties For other meanings of Atom, see Atom (disambiguation). ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ...


Francium's ability to be synthesized, trapped, and cooled, along with its relatively simple atomic structure have made it the subject of specialized spectroscopy experiments. These experiments have led to more specific information regarding energy levels and the coupling constants between subatomic particles.[17] Studies on the light emitted by laser-trapped francium-210 ions have provided accurate data on transitions between atomic energy levels. These experimental results have been fairly similar to those predicted by quantum theory.[18] Properties For other meanings of Atom, see Atom (disambiguation). ... Animation of the dispersion of light as it travels through a triangular prism. ... A quantum mechanical system can only be in certain states, so that only certain energy levels are possible. ... In physics, a coupling constant, usually denoted g, is a number that determines the strength of an interaction. ... Helium atom (schematic) Showing two protons (red), two neutrons (green) and two electrons (yellow). ... For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ...


History

As early as 1870, chemists thought that there should be an alkali metal beyond caesium, with an atomic number of 87.[4] It was then referred to by the provisional name eka-caesium.[19] Research teams attempted to locate and isolate this missing element, and at least four false claims were made that the element had been found before an authentic discovery was made. General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Standard atomic weight 132. ... Professor Dimitri Mendeleev published the first Periodic Table of the Atomic Elements in 1869 based on properties which appeared with some regularity as he laid out the elements from lightest to heaviest. ...


Erroneous and incomplete discoveries

Russian chemist D. K. Dobroserdov was the first scientist to claim to have found "eka-caesium". In 1925, he observed weak radioactivity in a sample of potassium, another alkali metal, and concluded that eka-caesium was contaminating the sample.[20] He then published a thesis on his predictions of the properties of eka-caesium, in which he named the element russium after his home country.[21] Shortly thereafter, Dobroserdov began to focus on his teaching career at the Polytechnic Institute of Odessa, and he did not pursue the element further.[20] General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ...


The following year, English chemists Gerald J. F. Druce and Frederick H. Loring analyzed X-ray photographs of manganese(II) sulfate.[21] They observed spectral lines which they presumed to be of eka-caesium. They announced their discovery of element 87 and proposed the name alkalinium, as it would be the heaviest alkali metal.[20] Year 1926 (MCMXXVI) was a common year starting on Friday (link will display the full calendar) of the Gregorian calendar. ... For other uses, see England (disambiguation). ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Manganese(II) sulfate monohydrate is a pink deliquescent solid. ...


In 1930, Fred Allison of the Alabama Polytechnic Institute claimed to have discovered element 87 when analyzing pollucite and lepidolite using his magneto-optical machine. Allison requested that it be named virginium after his home state of Virginia, along with the symbols Vi and Vm.[21][22] In 1934, however, H.G. MacPherson of UC Berkeley disproved the effectiveness of Allison's device and the validity of this false discovery.[23] Auburn University (AU) is a public university located in Auburn, Alabama with over 23,000 students and 1200 faculty. ... Pollucite is a mineral, one of the Zeolite group pf minerals. ... Crystal of lepidolite, Brazil Lepidolite (KLi2Al(Al,Si)3O10(F,OH)2) is a lilac or rose-violet colored phyllosilicate mineral of the mica group that is a secondary source of lithium. ... Magneto-optic effect: Any one of a number of phenomena in which an electromagnetic wave interacts with a magnetic field, or with matter under the influence of a magnetic field. ... This article is about the U.S. state. ... Sather tower (the Campanile) looking out over the San Francisco Bay and Mount Tamalpais. ...


In 1936, Romanian chemist Horia Hulubei and his French colleague Yvette Cauchois also analyzed pollucite, this time using their high-resolution X-ray apparatus.[20] They observed several weak emission lines, which they presumed to be those of element 87. Hulubei and Cauchois reported their discovery and proposed the name moldavium, along with the symbol Ml, after Moldavia, the Romanian province where they conducted their work.[21] In 1937, Hulubei's work was criticized by American physicist F. H. Hirsh Jr., who rejected Hulubei's research methods. Hirsh was certain that eka-caesium would not be found in nature, and that Hulubei had instead observed mercury or bismuth X-ray lines. Hulubei, however, insisted that his X-ray apparatus and methods were too accurate to make such a mistake. Because of this, Jean Baptiste Perrin, Nobel Prize winner and Hulubei's mentor, endorsed moldavium as the true eka-caesium over Marguerite Perey's recently-discovered francium. Perey, however, continuously criticized Hulubei's work until she was credited as the sole discoverer of element 87.[20] For other uses of Moldavia or Moldova, see Moldova (disambiguation). ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery Standard atomic weight 200. ... General Name, Symbol, Number bismuth, Bi, 83 Chemical series poor metals Group, Period, Block 15, 6, p Appearance lustrous pink Standard atomic weight 208. ... Jean Baptiste Perrin (b. ... The Nobel Prize (Swedish: ), as designated in Alfred Nobels will in 1895, is awarded in Physics, Chemistry, Physiology or Medicine, Literature, and Peace. ... Marguerite Catherine Perey (1909 - 1975) was a French physicist. ...


Perey's analysis

Eka-caesium was truly discovered in 1939 by Marguerite Perey of the Curie Institute in Paris, when she purified a sample of actinium-227 which had been reported to have a decay energy of 220 keV. However, Perey noticed decay particles with an energy level below 80 keV. Perey thought this decay activity might have been caused by a previously unidentified decay product, one which was separated during purification, but emerged again out of the pure actinium-227. Various tests eliminated the possibility of the unknown element being thorium, radium, lead, bismuth, or thallium. The new product exhibited chemical properties of an alkali metal (such as coprecipitating with caesium salts), which led Perey to believe that it was element 87, caused by the alpha decay of actinium-227.[19] Perey then attempted to determine the proportion of beta decay to alpha decay in actinium-227. Her first test put the alpha branching at 0.6%, a figure which she later revised to 1%.[24] Marguerite Catherine Perey (1909 - 1975) was a French physicist. ... The Curie Institute is a private non-profit foundation operating a research center on biophysics, cell biology and oncology and a hospital (Hôpital Claudius Régaud) specialized in treatment of cancer. ... This article is about the capital of France. ... General Name, Symbol, Number actinium, Ac, 89 Chemical series actinides Group, Period, Block 3, 7, f Appearance silvery Standard atomic weight (227) g·mol−1 Electron configuration [Rn] 6d1 7s2 Electrons per shell 2, 8, 18, 32, 18, 9, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight 232. ... This article is about the metal. ... General Name, Symbol, Number thallium, Tl, 81 Chemical series poor metals Group, Period, Block 13, 6, p Appearance silvery white Standard atomic weight 204. ... Alpha decay Alpha decay is a type of radioactive decay in which an atom emits an alpha particle (two protons and two neutrons bound together into a particle identical to a helium nucleus) and transforms (or decays) into an atom with a mass number 4 less and atomic number 2... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ...


Perey named the new isotope actinium-K (now referred to as francium-223)[19] and in 1946, she proposed the name catium for her newly-discovered element, as she believed it to be the most electropositive cation of the elements. Irène Joliot-Curie, one of Perey's supervisors, opposed the name due to its connotation of cat rather than cation.[19] Perey then suggested francium as an homage to the country in which she discovered it. This name was officially adopted by the International Union of Chemists in 1949,[4] becoming the second element after gallium to be named after France. It was assigned the symbol Fa, but this abbreviation was revised to the current Fr shortly thereafter.[25] Francium was the last naturally occurring element to be discovered, following rhenium in 1925.[19] Further research into francium's structure was carried out by, among others, Sylvain Lieberman and his team at CERN in the 1970s and 1980s.[26] Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... A cation is an ion with positive charge. ... Irène Joliot-Curie née Curie, (12 September 1897 – 17 March 1956) was a French scientist, the daughter of Marie SkÅ‚odowska-Curie and Pierre Curie and the wife of Frédéric Joliot-Curie. ... General Name, Symbol, Number gallium, Ga, 31 Chemical series poor metals Group, Period, Block 13, 4, p Appearance silvery white   Standard atomic weight 69. ... General Name, Symbol, Number rhenium, Re, 75 Chemical series transition metals Group, Period, Block 7, 6, d Appearance grayish white Standard atomic weight 186. ... CERN logo The European Organization for Nuclear Research (French: ), commonly known as CERN (see Naming), pronounced (or in French), is the worlds largest particle physics laboratory, situated just northwest of Geneva on the border between France and Switzerland. ...


Occurrence

In the MOT, a magnetic field is created by the copper solenoids. Neutral francium atoms enter the glass bulb from the left and are trapped by lasers.
In the MOT, a magnetic field is created by the copper solenoids. Neutral francium atoms enter the glass bulb from the left and are trapped by lasers.[27]

Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

Natural

Francium-223 is the result of the alpha decay of actinium-227 and can be found in trace amounts in uranium and thorium minerals.[3] In a given sample of uranium, there is estimated to be only one francium atom for every 1×1018 uranium atoms.[14] It is also calculated that there is at most 30 g of francium in the earth's crust at any time.[28] This makes it the second rarest element in the crust after astatine.[4][14] General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Standard atomic weight 232. ... For other uses, see Mineral (disambiguation). ... BIC pen cap, about 1 gram. ... Earth cutaway from core to exosphere. ... The abundance of a chemical element measures how relatively common the element is, or how much of the element there is by comparison to all other elements. ...


Synthesized

Francium can be synthesized in the nuclear reaction 197Au + 18O → 210Fr + 5n. This process, developed by Stony Brook Physics, yields francium isotopes with masses of 209, 210, and 211,[29] which are then isolated by the magneto-optic trap (MOT).[27] Other synthesis methods include bombarding radium with neutrons, and bombarding thorium with protons, deuterons, or helium ions.[24] Francium has not yet, as of 2006, been synthesized in amounts large enough to weigh.[3][4][14][30] The State University of New York at Stony Brook (SUNYSB), also known as Stony Brook University (SBU) is a public research university located in Stony Brook, New York (on the north side of Long Island, about 55 miles east of Manhattan, New York). ... Magneto-optic effect: Any one of a number of phenomena in which an electromagnetic wave interacts with a magnetic field, or with matter under the influence of a magnetic field. ... Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6500 of hydrogen (~154 PPM). ... For other uses, see Helium (disambiguation). ... This article is about the electrically charged particle. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ...


Isotopes

Main article: Isotopes of francium

There are 34 known isotopes of francium ranging in atomic mass from 199 to 232.[3] Francium has seven metastable nuclear isomers.[3] Francium-223 and francium-221 are the only isotopes that occur in nature, though the former is far more common.[31] Francium (Fr) Has no stable isotopes. ... Stylized lithium-7 atom: 3 protons, 4 neutrons & 3 electrons (~1800 times smaller than protons/neutrons). ... A metastable system with a weakly stable state (1), an unstable transition state (2) and a strongly stable state (3) Metastability is the ability of a non-equilibrium state to persist for some period of time. ... A nuclear isomer is a metastable or isomeric state of an atom caused by the excitation of a proton or neutron in its nucleus so that it requires a change in spin before it can release its extra energy. ...


Francium-223 is the most stable isotope with a half-life of 21.8 minutes,[3] and it is highly unlikely that an isotope of francium with a longer half-life will ever be discovered or synthesized.[24] Francium-223 is the fifth product of the actinium decay series as the daughter isotope of actinium-227.[16] Francium-223 then decays into radium-223 by beta decay (1149 keV decay energy), with a minor (0.006%) alpha decay path to astatine-219 (5.4 MeV decay energy).[32] General Name, Symbol, Number actinium, Ac, 89 Chemical series actinides Group, Period, Block 3, 7, f Appearance silvery Standard atomic weight (227) g·mol−1 Electron configuration [Rn] 6d1 7s2 Electrons per shell 2, 8, 18, 32, 18, 9, 2 Physical properties Phase solid Density (near r. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... The decay energy is the energy released by a nuclear decay. ... Alpha decay Alpha decay is a type of radioactive decay in which an atom emits an alpha particle (two protons and two neutrons bound together into a particle identical to a helium nucleus) and transforms (or decays) into an atom with a mass number 4 less and atomic number 2...


Francium-221 has a half-life of 4.8 minutes.[3] It is the ninth product of the neptunium decay series as a daughter isotope of actinium-225.[16] Francium-221 then decays into astatine-217 by alpha decay (6.457 MeV decay energy).[3] General Name, Symbol, Number neptunium, Np, 93 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery metallic Standard atomic weight (237) g·mol−1 Electron configuration [Rn] 5f4 6d1 7s2 Electrons per shell 2, 8, 18, 32, 22, 9, 2 Physical properties Phase solid Density (near r. ...


The least stable ground state isotope is francium-215, with a half-life of 0.12 μs. (9.54 MeV alpha decay to astatine-211):[3] Its metastable isomer, francium-215m, is less stable still, with a half-life of only 3.5 ns.[33] In physics, the ground state of a quantum mechanical system is its lowest-energy state. ...


See also

References

  1. ^ Actually the least unstable isotope, Fr-223
  2. ^ Some synthetic elements, like technetium, have later been found in nature.
  3. ^ a b c d e f g h i j k l CRC Handbook of Chemistry and Physics, vol. 4, CRC, 2006, pp. 12, 0-8493-0474-1
  4. ^ a b c d e f g Price, Andy (2004-12-20). Francium. Retrieved on 2007-03-25.
  5. ^ Winter, Mark. Electron Configuration. Francium. The University of Sheffield. Retrieved on 2007-04-18.
  6. ^ Pauling, Linus (1960). The Nature of the Chemical Bond (3rd Edn.). Cornell University Press, 93. 
  7. ^ Winter, Mark. Electronegativies. Caesium. The University of Sheffield. Retrieved on 2007-05-09. Pauling places caesium and francium with the same electronegativity.
  8. ^ Kozhitov, L. V.; Kol'tsov, V. B., and Kol'tsov, A. V. (2003-02-21). "Evaluation of the Surface Tension of Liquid Francium". Inorganic Materials 39 (11): 1138–1141. Springer Science & Business Media B.V.. Retrieved on 2007-04-14. 
  9. ^ E. K. Hyde. Radiochemical Methods for the Isolation of Element 87 (Francium). J. Am. Chem. Soc. 1952, 74, 4181-4184.[1].
  10. ^ E. N K. Hyde Radiochemistry of Francium,Subcommittee on Radiochemistry, National Academy of Sciences-National Research Council; available from the Office of Technical Services, Dept. of Commerce, 1960.
  11. ^ A. G. Maddock. Radioactivity of the heavy elements. Q. Rev., Chem. Soc., 1951, 3, 270–314. doi:10.1039/QR9510500270
  12. ^ Winter, Mark. Uses. Francium. The University of Sheffield. Retrieved on 2007-03-25.
  13. ^ Bentor, Yinon. Chemical Element.com - Francium. Retrieved on 2007-03-25.
  14. ^ a b c d e Emsley, John (2001). Nature's Building Blocks. Oxford: Oxford University Press, 151–153. 0-19-850341-5. 
  15. ^ Gagnon, Steve. Francium. Jefferson Science Associates, LLC. Retrieved on 2007-04-01.
  16. ^ a b c Considine, Glenn D., ed. (2005), "Chemical Elements", Van Nostrand's Encyclopedia of Chemistry, New York: Wylie-Interscience, pp. 332, 0-471-61525-0
  17. ^ Gomez, E; Orozco, L A, and Sprouse, G D (2005-11-07). "Spectroscopy with trapped francium: advances and perspectives for weak interaction studies". Rep. Prog. Phys. 69 (1): 79–118. doi:10.1088/0034-4885/69/1/R02. Retrieved on 2007-04-11. 
  18. ^ Peterson, I. "Creating, cooling, trapping francium atoms", Science News, 1996-05-11, pp. 294. Retrieved on 2007-04-11. 
  19. ^ a b c d e Adloff, Jean-Pierre; Kaufman, George B. (2005-09-25). Francium (Atomic Number 87), the Last Discovered Natural Element. The Chemical Educator 10 (5). Retrieved on 2007-03-26.
  20. ^ a b c d e Fontani, Marco (2005-09-10). "The Twilight of the Naturally-Occurring Elements: Moldavium (Ml), Sequanium (Sq) and Dor (Do)". International Conference on the History of Chemistry: 1–8. Retrieved on 2007-04-08. 
  21. ^ a b c d Van der Krogt, Peter (2006-01-10). Francium. Elementymology & Elements Multidict. Retrieved on 2007-04-08.
  22. ^ "Alabamine & Virginium", TIME, 1932-02-15. Retrieved on 2007-04-01. 
  23. ^ MacPherson, H. G. (1934-12-21). "An Investigation of the Magneto-Optic Method of Chemical Analysis". Physical Review 47 (4): 310–315. American Physical Society. doi:10.1103/PhysRev.47.310. Retrieved on 2007-04-08. 
  24. ^ a b c "Francium", McGraw-Hill Encyclopedia of Science & Technology, vol. 7, McGraw-Hill Professional, 2002, pp. 493–494, 0-07-913665-6
  25. ^ Grant, Julius (1969), "Francium", Hackh's Chemical Dictionary, McGraw-Hill, pp. 279–280
  26. ^ History. Francium. SUNY Stony Brook Physics & Astronomy (2007-02-20). Retrieved on 2007-03-26.
  27. ^ a b Cooling and Trapping. Francium. SUNY Stony Brook Physics & Astronomy (2007-02-20). Retrieved on 2007-05-01.
  28. ^ Winter, Mark. Geological information. Francium. The University of Sheffield. Retrieved on 2007-03-26.
  29. ^ Production of Francium. Francium. SUNY Stony Brook Physics & Astronomy (2007-02-20). Retrieved on 2007-03-26.
  30. ^ Francium. Los Alamos Chemistry Division (2003-12-15). Retrieved on 2007-03-29.
  31. ^ Considine, Glenn D., ed. (2005), "Francium", Van Nostrand's Encyclopedia of Chemistry, New York: Wylie-Interscience, pp. 679, 0-471-61525-0
  32. ^ National Nuclear Data Center (1990). Table of Isotopes decay data. Brookhaven National Laboratory. Retrieved on 2007-04-04..
  33. ^ National Nuclear Data Center (2003). Fr Isotopes. Brookhaven National Laboratory. Retrieved on 2007-04-04..

General Name, Symbol, Number technetium, Tc, 43 Chemical series transition metals Group, Period, Block 7, 5, d Appearance silvery gray metal Standard atomic weight [98](0) g·mol−1 Electron configuration [Kr] 4d5 5s2 Electrons per shell 2, 8, 18, 13, 2 Physical properties Phase solid Density (near r. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 84th day of the year (85th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 108th day of the year (109th in leap years) in the Gregorian calendar. ... Linus Carl Pauling (February 28, 1901 – August 19, 1994) was an American quantum chemist and biochemist. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 129th day of the year (130th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 104th day of the year (105th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 84th day of the year (85th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 84th day of the year (85th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 91st day of the year (92nd in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 101st day of the year (102nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 101st day of the year (102nd in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 268th day of the year (269th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... March 26 is the 85th day of the year (86th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 8 is the 98th day of the year (99th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 8 is the 98th day of the year (99th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 91st day of the year (92nd in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 8 is the 98th day of the year (99th in leap years) in the Gregorian calendar. ... The State University of New York at Stony Brook (SUNYSB), also known as Stony Brook University (SBU) is a public research university located in Stony Brook, New York (on the north side of Long Island, about 55 miles east of Manhattan, New York). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... March 26 is the 85th day of the year (86th in leap years) in the Gregorian calendar. ... The State University of New York at Stony Brook (SUNYSB), also known as Stony Brook University (SBU) is a public research university located in Stony Brook, New York (on the north side of Long Island, about 55 miles east of Manhattan, New York). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 121st day of the year (122nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... March 26 is the 85th day of the year (86th in leap years) in the Gregorian calendar. ... The State University of New York at Stony Brook (SUNYSB), also known as Stony Brook University (SBU) is a public research university located in Stony Brook, New York (on the north side of Long Island, about 55 miles east of Manhattan, New York). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... March 26 is the 85th day of the year (86th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 88th day of the year (89th in leap years) in the Gregorian calendar. ... ≠ Aerial view of Brookhaven National Laboratory. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 94th day of the year (95th in leap years) in the Gregorian calendar. ... ≠ Aerial view of Brookhaven National Laboratory. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 94th day of the year (95th in leap years) in the Gregorian calendar. ...

External links

Wikimedia Commons has media related to:
Look up francium in
Wiktionary, the free dictionary.

  Results from FactBites:
 
CRCPress Periodic Table Online: Cadmium (290 words)
Francium, the heaviest known member of the alkali metal series, occurs as a result of an alpha disintegration of actinium.
Because all known isotopes of francium are highly unstable, knowledge of the chemical properties of this element comes from radiochemical techniques.
It is thought that the francium atoms could serve as miniature laboratories for probing interactions between electrons and quarks.
Francium (217 words)
Francium is a chemical element in the periodic table that has the symbol Fr and atomic number 87.
Francium is the heaviest alkali metal and occurs as a result of actinium's alpha decay and can be artificially made by bombarding thorium with protons.
Chemically, the properties of francium are closest to those of caesium.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m