Mendelevium
What is Mendelevium
Mendelevium (pronounced as men-deh-LEE-vee-em) is a radioactive metal that belongs to the family of actinides and represented by the chemical symbol Md. Its most stable isotope is Md-258 with a half-life of 51.5 days [1, 4].
History
Origin of its Name: The element is named in honor of Dmitri Mendeleev, a Russian chemist who formulated one of the first periodic tables [1].
Who Discovered it: Albert Ghiorso and his team of researchers comprising of Gregory Chopin, Bernard Harvey, Glenn Seaborg, and Stanley Thompson were responsible for its discovery [1].
When and Where was Mendelevium Discovered
In 1955, Ghiorso and his team at Berkeley, California, conducted an all-night experiment where a sample of einsteinium-253 was bombarded with alpha particles in a cyclotron to produce a new isotope, later detected as mendelevium-256 with a half-life of about 78 minutes. After this, several other isotopes of the new metal were synthesized at the laboratory [1].
Identification |
|||
Atomic number | 101 [1] | ||
CAS number | 7440-11-1 [1] | ||
Position in the periodic table [1] | Group | Period | Block |
Actinides | 7 | f |
Properties and Characteristics of Mendelevium
General Properties |
||
Relative atomic mass | 258 [1] | |
Atomic mass | 258 atomic mass units [5] | |
Physical Properties |
||
Color/appearance | Unknown [1] | |
Melting point/freezing point | 827°C (1521°F) [1] | |
Boiling point | Unknown [1] | |
Density | Unknown [1] | |
State at standard room temperature (solid/liquid/gas) | Solid [1] | |
Electrical conductivity | Unknown [1] | |
Chemical Properties |
||
Oxidation state/Oxidation number | +2, +3 [1] |
Atomic Data of Mendelevium (Element 101)
Valence electrons | 3 [6] | ||||||
Electron configuration (noble gas configuration) | [Rn] 5f137s2 [1] | ||||||
Atomic structure [3] | |||||||
– Number of Electrons | 101 | ||||||
– Number of Neutrons | 157 | ||||||
– Number of Protons | 101 | ||||||
Radius of atom | |||||||
– Atomic Radius | 2.46 Å [1] | ||||||
– Covalent Radius | 1.73 Å [1] | ||||||
Ionization energy [1]
(kJmol-1) |
1st | 2nd | 3rd | 4th | 5th | 6th | 7th |
634.87 | – | – | – | – | – | – |
What is Mendelevium Used for
The short half-life of Md makes it difficult to study its properties in detail, and determine any uses. As a result, it is artificially synthesized whenever required for scientific studies [1].
Interesting Facts
- As naming the element after a Russian chemist was a bold decision taken in the middle of the Cold War, Glenn Seaborg had to take permission from the U.S government before officially declaring the discovery of mendelevium [7].
- The proposed symbol for the element was Mv, but IUPAC changed it to Md in 1957, at their assembly in Paris [7].
Mendelevium Cost
Since the element is artificially prepared in the laboratory, it cannot be commercially availed.
References
- http://www.rsc.org/periodic-table/element/101/mendelevium
- https://education.jlab.org/itselemental/ele101.html
- https://www.chemicool.com/elements/mendelevium.html
- https://education.jlab.org/itselemental/iso101.html
- http://hobart.k12.in.us/ksms/PeriodicTable/mendelevium.htm
- http://periodictable.com/Elements/101/data.html
- https://www.thoughtco.com/mendelevium-facts-4126518