105 rutherfordium ← dubnium → seaborgium Ta ↑ Db ↓ (Upp) periodic table
General
Name, Symbol, Number	dubnium, Db, 105
Chemical series	transition metals
Group, Period, Block	5, 7, d
Appearance	unknown, probably silvery white or metallic gray
Atomic mass	(262) g/mol
Electron configuration	perhaps [Rn] 5f14 6d3 7s2 (guess based on tantalum)
Electrons per shell	2, 8, 18, 32, 32, 11, 2
Phase	presumably a solid
CAS registry number	53850-35-4
References

Dubnium (formerly also called Eka-Tantalum, Hahnium and Unnilpentium) is a chemical element in the periodic table that has the symbol Db and atomic number 105. This is a highly radioactive synthetic element whose most stable isotope has a half life of 32 hours (²⁶⁸Db). This relatively high stability compared to the surrounding elements on the periodic table gives evidence that by manipulating the number of neutrons in a nucleus, one can alter the stabilities of such nuclei. General Name, Symbol, Number rutherfordium, Rf, 104 Chemical series transition metals Group, Period, Block 4, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (261) g/mol Electron configuration probably [Rn] 5f14 6d2 7s2 Electrons per shell 2, 8, 18, 32, 32, 10, 2 Phase presumably a... General Name, Symbol, Number seaborgium, Sg, 106 Chemical series transition metals Group, Period, Block 6, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (266) g/mol Electron configuration perhaps [Rn] 5f14 6d4 7s2 (guess based on tungsten) Electrons per shell 2, 8, 18, 32, 32, 12... General Name, Symbol, Number tantalum, Ta, 73 Chemical series transition metals Group, Period, Block 5, 6, d Appearance gray blue Atomic mass 180. ... Image File history File links Dubnium in periodic table of elements, from French Wikipedia. ... For information about the period table of elements, see Periodic table. ... This is a list of chemical elements, sorted by name and color coded according to type of element. ... Categories: Chemical elements ... sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex... In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc and scandium. ... A periodic table group is a vertical column in the periodic table of the chemical elements. ... In the periodic table of the elements, a period is a row of the table. ... A block of the periodic table of elements is a set of adjacent groups. ... A Group 5 element is the series of elements in group 5 (IUPAC style) in the periodic table, which consists of vanadium (V), niobium (Nb), tantalum (Ta), and dubnium (Db). ... A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements. ... D Block is a rap group based in Yonkers, New York. ... ... The atomic mass of a chemical element (also known as the relative atomic mass or average atomic mass or atomic weight) is the average atomic mass of all the chemical elements isotopes as found in a particular environment, weighted by isotopic abundance. ... To help compare different orders of magnitude we list here masses between 60. ... It has been suggested that Energy level be merged into this article or section. ... General Name, Symbol, Number radon, Rn, 86 Chemical series noble gases Group, Period, Block 18, 6, p Appearance colorless Atomic mass (222) g/mol Electron configuration [Xe] 4f14 5d10 6s2 6p6 Electrons per shell 2, 8, 18, 32, 18, 8 Physical properties Phase gas Melting point 202 K (-71 °C... General Name, Symbol, Number tantalum, Ta, 73 Chemical series transition metals Group, Period, Block 5, 6, d Appearance gray blue Atomic mass 180. ... Properties The electron is a fundamental subatomic particle that carries a negative electric charge. ... A quantum mechanical system can only be in certain states, so that only certain energy levels are possible. ... 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. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... A chemical element, often called simply element, is a chemical substance that cannot be divided or changed into other chemical substances by any ordinary chemical technique. ... The periodic table of the chemical elements is a tabular method of displaying the chemical elements, first devised in 1869 by the Russian chemist Dmitri Mendeleev. ... The atomic number (Z) is a term used in chemistry and physics to represent the number of protons found in the nucleus of an atom. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... The chemical elements labelled as synthetic are unstable, with a half-life so short (ranging from a fraction of millisecond to a few million years) relative to the age of the Earth that any atoms of that element that may have been present when the Earth formed have long since... Isotopes are forms of an element whose nuclei have the same atomic number - the number of protons in the nucleus - but different mass numbers because they contain different numbers of neutrons. ... Half-Life is a science fiction first-person shooter computer game developed by Valve Software and published by Sierra Entertainment in 1998, based on a heavily-modified Quake game engine. ... To help compare orders of magnitude of different times this page lists times between 104 seconds and 105 seconds (2. ...

History

Dubnium (named after Dubna, Russia) was reportedly first synthesized in 1967 at the Joint Institute for Nuclear Research in Dubna, Russia (reportedly producing element ²⁶⁰105 and element ²⁶¹105 by bombarding ²⁴³Am with ²²Ne). In late April 1970 researchers led by Albert Ghiorso working at the University of California, Berkeley had positively identified element 105. Dubna is a small city located in central Russia, in the Taldomsky district of Moscow Oblast, approximately 125 km north of Moscow, on the banks of the Volga river. ... This article or section should be merged with Timeline of chemical element discovery The story of the discoveries of the chemical elements is presented here in chronological order. ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar. ... The Joint Institute for Nuclear Research, JINR (Объединённый институт ядерных исследований, ОИЯИ in Russian) in Dubna, Moscow Oblast (120 km north of Moscow), Russia is an international research centre for nuclear sciences, involving around 1000 scientists from eighteen states (Armenia, Azerbaijan, Belarus, Bulgaria, Cuba, Czech Republic, Georgia, Kazakhstan, DPR Korea, Moldova, Mongolia, Poland,Romania, Russia... Dubna is a small city located in central Russia, in the Taldomsky district of Moscow Oblast, approximately 125 km north of Moscow, on the banks of the Volga river. ... General Name, Symbol, Number americium, Am, 95 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery white Atomic mass (243) g/mol Electron configuration [Rn] 5f7 7s2 Electrons per shell 2, 8, 18, 32, 25, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number neon, Ne, 10 Chemical series noble gases Group, Period, Block 18, 2, p Appearance colorless Atomic mass 20. ... 1970 (MCMLXX) was a common year starting on Thursday (the link is to a full 1970 calendar). ... Albert Ghiorso (b. ... University of California, Berkeley The University of California, Berkeley (also known as California, Cal, UCB, UC Berkeley, The University of California, or simply Berkeley) is a public, coeducational university situated east of the San Francisco Bay in Berkeley, California, overlooking the Golden Gate. ...

The American team synthesized the element by bombarding a target ²⁴⁹Cf with a beam of 84 MeV nitrogen nuclei in the Heavy Ion Linear Accelerator (a particle accelerator), which produced element ²⁶⁰105 with a half-life of 1.6 seconds. Atoms of element 105 were detected conclusively on March 5, 1970 but there is evidence that this element had already been formed at Berkeley a year earlier using the same method. General Name, Symbol, Number californium, Cf, 98 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (251) g/mol Electron configuration [Rn] 5f10 7s2 Electrons per shell 2, 8, 18, 32, 28, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... A 1960s single stage 2MeV linear Van de Graaff accelerator, here opened for maintenance A particle accelerator is a device that uses electric and/or magnetic fields to propel electrically charged particles to high speeds. ... 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. ... Properties In chemistry and physics, an atom (Greek άτομον meaning indivisible) is the smallest possible particle of a chemical element that retains its chemical properties. ... March 5 is the 64th day of the year in the Gregorian Calendar (65th in leap years). ... 1970 (MCMLXX) was a common year starting on Thursday (the link is to a full 1970 calendar). ...

The Berkeley scientists later tried to confirm the Soviet findings using more sophisticated methods but were not successful. They proposed that the new element should be named hahnium (symbol Ha) in honor of the late German scientist Otto Hahn. Consequently this was the name that most American and Western European scientists used. State motto (Russian): Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) (Translated: Workers of the world, unite!) Capital Moscow Official language None; Russian (de facto) Government Federation of Socialist republics Area  - Total  - % water 1st before collapse 22,402,200 km² Approx. ... Otto Hahn (March 8, 1879 – July 28, 1968) was a German chemist. ...

An element naming controversy erupted over what to name this element after Russian researchers protested. The International Union of Pure and Applied Chemistry (IUPAC) thus adopted unnilpentium (symbol Unp) as a temporary, systematic element name. However in 1997 they resolved the dispute and adopted the current name, dubnium (symbol Db), after the city that contains the Russian Joint Institute for Nuclear Research. The names for the chemical elements 104 to 108 have been the subject of a major controversy starting in the 1960s which was only finally resolved in 1997. ... IUPAC logo The International Union of Pure and Applied Chemistry (IUPAC) is an international non-governmental organization devoted to the advancement of chemistry. ... In chemistry, heavy transuranic elements receive a permanent name and symbol only after their discovery has been confirmed. ... 1997 (MCMXCVII in Roman) is a common year starting on Wednesday of the Gregorian calendar. ... The Joint Institute for Nuclear Research, JINR (Объединённый институт ядерных исследований, ОИЯИ in Russian) in Dubna, Moscow Oblast (120 km north of Moscow), Russia is an international research centre for nuclear sciences, involving around 1000 scientists from eighteen states (Armenia, Azerbaijan, Belarus, Bulgaria, Cuba, Czech Republic, Georgia, Kazakhstan, DPR Korea, Moldova, Mongolia, Poland,Romania, Russia...

References

• Los Alamos National Laboratory - Dubnium

External links

Wikimedia Commons has media related to:

Dubnium

• WebElements.com - Dubnium