101 fermium ← mendelevium → nobelium Tm ↑ Md ↓ (Upu) Periodic Table - Extended Periodic Table
General
Name, Symbol, Number	mendelevium, Md, 101
Chemical series	actinides
Group, Period, Block	n/a, 7, f
Appearance	unknown, probably silvery white or metallic gray
Atomic mass	(258) g·mol−1
Electron configuration	[Rn] 5f13 7s2
Electrons per shell	2, 8, 18, 32, 31, 8, 2
Physical properties
Phase	solid
Melting point	1100 K (827 °C, 1521 °F)
Atomic properties
Oxidation states	2, 3
Electronegativity	1.3 (Pauling scale)
Ionization energies	1st: 635 kJ/mol
Miscellaneous
Magnetic ordering	no data
CAS registry number	7440-11-1
Selected isotopes
Main article: Isotopes of mendelevium iso NA half-life DM DE (MeV) DP 257Md syn 5.52 h ε 0.406 257Fm α 7.558 253Es SF - - 258Md syn 51.5 d ε 1.230 258Fm 260Md syn 31.8 d SF - - α 7.000 256Es ε - 260Fm β- 1.000 260No
References

Mendelevium (IPA: /ˌmɛndəˈlɛviəm/), also known as unnilunium (IPA: /ˌjuːniˈluːniəm/, symbol Unu) is a synthetic element in the periodic table with the symbol Md (formerly Mv) and the atomic number 101. A metallic radioactive transuranic element of the actinides, mendelevium is synthesized by bombarding einsteinium with alpha particles and was named after Dmitri Mendeleev. General Name, Symbol, Number fermium, Fm, 100 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (257) g·mol−1 Electron configuration [Rn] 5f12 7s2 Electrons per shell 2, 8, 18, 32, 30, 8, 2 Physical properties Phase solid... 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... General Name, Symbol, Number thulium, Tm, 69 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery gray Atomic mass 168. ... Image File history File links Download high resolution version (890x260, 0 KB)stub for unified link coding, copy of File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... This is a standard display of the periodic table of elements. ... This 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. ... 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... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89 - 103[1]. The actinide series is named after actinium. ... 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. ... 6 *Lanthanides 7 **Actinides IUPAC has not recommended a specific format for the periodic table, so different conventions are permitted and are often used for the group number of lanthanides and actinides. ... A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements. ... The f-block of the periodic table of elements consists of those elements for which, in the atomic ground state, the highest-energy electrons occupy f-orbitals. ... Color is an important part of the visual arts. ... The atomic mass of a chemical element is the mass of an atom at rest, most often expressed in unified atomic mass units. ... To help compare different orders of magnitude we list here masses between 60. ... 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 (eg, a crystal). ... General Name, Symbol, Number radon, Rn, 86 Chemical series noble gases Group, Period, Block 18, 6, p Appearance colorless Atomic mass (222) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p6 Electrons per shell 2, 8, 18, 32, 18, 8 Physical properties Phase gas Density (0 °C, 101. ... e- redirects here. ... 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. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... Fahrenheit is a temperature scale named after the German physicist Daniel Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ... The oxidation number of an element in a molecule or complex is the charge that it would have if all the ligands were removed along with the electron pairs that were shared with the central atom[1]. It is used in the inorganic nomenclature of inorganic compounds. ... 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. ... Magnetic lines of force of a bar magnet shown by iron filings on paper In physics, magnetism is one of the phenomena by which materials exert an attractive or repulsive force on other materials. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Mendelevium (Md) Has no stable isotopes. ... Isotopes are any of the several different forms of an element each having different atomic mass. ... 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. ... In physics, the decay mode describes a particular way a particle decays. ... The decay energy is the energy released by a nuclear decay. ... An electronvolt (symbol: eV) is the amount of energy gained by a single unbound electron when it falls through an electrostatic potential difference of one volt. ... 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. ... (Redirected from 1 E s) An order of magnitude is the class of scale or magnitude of any amount, where each class contains values of a fixed ratio to the class preceding it. ... Electron capture is a decay mode for isotopes that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to emit a positron; however, it continues to be a viable decay mode for radioactive isotopes that can decay by positron... General Name, Symbol, Number fermium, Fm, 100 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (257) g·mol−1 Electron configuration [Rn] 5f12 7s2 Electrons per shell 2, 8, 18, 32, 30, 8, 2 Physical properties Phase solid... 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 einsteinium, Es, 99 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (252) g·mol−1 Electron configuration [Rn] 5f11 7s2 Electrons per shell 2, 8, 18, 32, 29, 8, 2 Physical properties Phase solid... Spontaneous fission (SF) is a form of radioactive decay characteristic of very heavy isotopes, and is theoretically possible for any atomic nucleus whose mass is greater than or equal to 100 amu (elements near ruthenium). ... 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. ... To help compare orders of magnitude of different times this page lists times between 106 seconds (a megasecond) and 107 seconds (11. ... General Name, Symbol, Number fermium, Fm, 100 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (257) g·mol−1 Electron configuration [Rn] 5f12 7s2 Electrons per shell 2, 8, 18, 32, 30, 8, 2 Physical properties Phase solid... 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. ... Water, Rabbit, and Deer: three of the 20 day symbols in the Aztec calendar, from the Aztec Sun Stone. ... General Name, Symbol, Number einsteinium, Es, 99 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (252) g·mol−1 Electron configuration [Rn] 5f11 7s2 Electrons per shell 2, 8, 18, 32, 29, 8, 2 Physical properties Phase solid... General Name, Symbol, Number fermium, Fm, 100 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (257) g·mol−1 Electron configuration [Rn] 5f12 7s2 Electrons per shell 2, 8, 18, 32, 30, 8, 2 Physical properties Phase solid... 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 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... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... For information on how to read IPA transcriptions of English words see here. ... For information on how to read IPA transcriptions of English words see here. ... 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... 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. ... It has been suggested that List of elements by atomic number be merged into this article or section. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily loses electrons to form positive ions (cations) and has metallic bonds between metal atoms. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... In chemistry, transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, the atomic number of Uranium. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89 - 103[1]. The actinide series is named after actinium. ... General Name, Symbol, Number einsteinium, Es, 99 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (252) g·mol−1 Electron configuration [Rn] 5f11 7s2 Electrons per shell 2, 8, 18, 32, 29, 8, 2 Physical properties Phase solid... An alpha particle is deflected by a magnetic field Alpha particles (named after the first letter in the Greek alphabet, α) are a highly ionizing form of particle radiation which have low penetration. ... Portrait of Dimitri Mendeleyev by Ilya Repin Dmitri Mendeleev (Russian: , Dmitriy Ivanovich Mendeleyev  ) (8 February [O.S. 27 January] 1834 in Tobolsk – 2 February [O.S. 20 January] 1907 in Saint Petersburg), was a Russian chemist. ...

Notable characteristics

Researchers have shown that mendelevium has a moderately stable dipositive (II) oxidation state in addition to the more characteristic (for actinide elements) tripositive (III) oxidation state. ²⁵⁶Md has been used to find out some of the chemical properties of this element while in an aqueous solution. There are no other uses of mendelevium and only trace amounts of the element have ever been produced. In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. ... Drinking water This article focuses on water as we experience it every day. ...

History

Mendelevium (for Dmitri Mendeleyev, surname commonly spelt as Mendeleev, Mendeléef, or even Mendelejeff, and first name sometimes spelt as Dmitry or Dmitriy) was first synthesized by Albert Ghiorso (team leader), Glenn T. Seaborg, Bernard Harvey,Greg Choppin, and Stanley G. Thompson in early 1955 at the University of California, Berkeley. The team produced ²⁵⁶Md (half-life of 76 minutes) when they bombarded an ²⁵³Es target with alpha particles (helium nuclei) in the Berkeley Radiation Laboratory's 60-inch cyclotron (²⁵⁶Md was the first element to be synthesized one-atom-at-a-time). Element 101 was the ninth transuranic element synthesized. Portrait of Dmitri Mendeleyev by Ilya Repin Dmitri Ivanovich Mendeleyev (Russian: â–¶(?)) (8 February [O.S. 27 January] 1834 in Tobolsk – 2 February [O.S. 20 January] 1907 in Saint Petersburg), was a Russian chemist. ... 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. ... Albert Ghiorso (b. ... Glenn T. Seaborg Glenn Theodore Seaborg (April 19, 1912 – February 25, 1999) was an American chemist prominent in the discovery and isolation of ten transuranic elements including plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium and seaborgium, which was named in his honor. ... 1955 (MCMLV) was a common year starting on Saturday of the Gregorian calendar. ... 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. ... General Name, Symbol, Number einsteinium, Es, 99 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (252) g·mol−1 Electron configuration [Rn] 5f11 7s2 Electrons per shell 2, 8, 18, 32, 29, 8, 2 Physical properties Phase solid... An alpha particle is deflected by a magnetic field Alpha particles (named after the first letter in the Greek alphabet, α) are a highly ionizing form of particle radiation which have low penetration. ... For other uses of this term, see Helium (disambiguation). ... The Berkeley Lab is perched on a hill overlooking the Berkeley central campus and San Francisco Bay. ... A pair of Dee electrodes with loops of coolant pipes on their surface at the Lawrence Hall of Science. ... In chemistry, transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, the atomic number of Uranium. ...

Isotopes

15 radioisotopes of mendelevium have been characterized, with the most stable being ²⁵⁸Md with a half-life of 51.5 days, ²⁶⁰Md with a half-life of 31.8 days, and ²⁵⁷Md with a half-life of 5.52 hours. All of the remaining radioactive isotopes have half-lives that are less than 97 minutes, and the majority of these have half-lives that are less than 5 minutes. This element also has 1 meta state, ^258mMd (t_½ 57 minutes). The isotopes of mendelevium range in atomic weight from 245.091 amu (²⁴⁵Md) to 260.104 amu (²⁶⁰Md). A radionuclide is an atom with an unstable nucleus. ... 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 set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... A nuclear isomer is a metastable 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. ... ... The unified atomic mass unit (u), or Dalton (Da), is a small unit of mass used to express atomic and molecular masses. ...

References

• Los Alamos National Laboratory - Mendelevium
• Guide to the Elements - Revised Edition, Albert Stwertka, (Oxford University Press; 1998) ISBN 0-19-508083-1
• It's Elemental - Mendelevium

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• WebElements.com - Mendelevium