This process, developed by Stony Brook Physics, yields francium isotopes with masses of 209, 210, and 211,[37] which are then isolated by the magneto-optical trap (MOT).[36] The production rate of a particular isotope depends on the energy of the oxygen beam. An 18O beam from the Stony Brook LINAC creates 210Fr in the gold target with the nuclear reaction 197Au + 18O → 210Fr + 5n. The production required some time to develop and understand. It was critical to operate the gold target very close to its melting point and to make sure that its surface was very clean. The nuclear reaction embeds the francium atoms deep in the gold target, and they must be removed efficiently. The atoms quickly diffuse to the surface of the gold target and are released as ions, but this does not happen every time. The francium ions are guided by electrostatic lenses until they land in a surface of hot yttrium and become neutral again. The francium is then injected into a glass bulb. A magnetic field and laser beams ...

Francium is one of the most unstable of the naturally occurring elements: its longest-lived isotope, francium-223, has a half-life of only 22 minutes. The only comparable element is astatine, whose most stable natural isotope, astatine-219 (the alpha daughter of francium-223), has a half-life of 56 seconds, although synthetic astatine-210 is much longer-lived with a half-life of 8.1 hours.[5] All isotopes of francium decay into astatine, radium, or radon.[5] Francium-223 also has a shorter half-life than the longest-lived isotope of each synthetic element up to and including element 105, dubnium.[6] Francium is an alkali metal whose chemical properties mostly resemble those of caesium.[6] A heavy element with a single valence electron,[7] it has the highest equivalent weight of any element.[6] Liquid francium-if created-should have a surface tension of 0.05092 N/m at its melting point.[8] Franciums melting point was estimated to be around 8.0 °C (46.4 °F, 281.0 K).[1] The melting point is ...

The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a

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Intensely radioactive, short lived metal element. Primarily occurs as a trace amount (a few ppm) in uranium or thorium minerals where it is a decay product of uranium and/or thorium. ...

alkali metal definition: Any of a small grouping of soft, white, low-density, low-melting, highly reactive metallic elements, including lithium, sodium, potassium, rubidium, cesium, and francium.; some…

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COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides {monoborane, diborane or addition complexes thereof} C01B 6/00; salts of oxyacids of halogens C01B 11/00; peroxides, salts of peroxyacids C01B 15/00; sulfides C01B 17/22; thiosulfates, dithionites, polythionates C01B 17/64; compounds containing selenium or tellurium C01B 19/00; binary compounds of nitrogen with metals C01B 21/06; azides C01B 21/08; {compounds other than ammonia and cyanogen, containing nitrogen and other non-metals C01B 21/082}; metal amides C01B 21/092; nitrites C01B 21/50; phosphides C01B 21/50; {compounds of noble gases C01B 23/0005}; phosphides C01B 25/08; salts of oxyacids of phosphorus C01B 25/16; carbides C01B 32/90; compounds containing silicon C01B 33/00; compounds containing boron C01B 35/00; cyanides C01C 3/08; salts of cyanic acid C01C 3/14; salts of cyanamide C01C 3/16; thiocyanates C01C 3/20 ...

Chemical series of the periodic table The Detailed Table is a smaller version of the Huge Table. ... A periodic table group 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). ... The alkaline earth metals are a series of elements comprising Group 2 (IUPAC style) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra). ... A Group 3 element is an element in periodic table group 3 (IUPAC style) in the periodic table, which consists of: scandium (21) yttrium (39) lanthanum (57) - lutetium (71) actinium (89) - lawrencium (103) All of these elements are classed in Group 3 because their outer shell holds three electrons. ... A Group 4 element is an element in periodic table group 4 (IUPAC style) in the periodic table, which consists of: ...