Meitnerium

Meitnerium is a [|chemical element] with the symbol Mt and [|atomic number] 109. It is placed as the heaviest member of group 9 (or VIII) in the periodic table but a sufficiently stable isotope is not known at this time which would allow chemical experiments to confirm its position as a heavier [|homologue] to [|iridium], unlike its lighter neighbors. It was first synthesized in 1982 and several isotopes are currently known. The heaviest and the most stable isotope known is 278Mt, with a [|half-life] of ~8 s

Atomic Number: 109 Atomic Weight: 278 Melting Point: Unknown Boiling Point: Unknown Density: Unknown Phase at Room Temperature: Solid Element Classification: Metal Period Number: 7 Group Number: 9 Group Name: none Radioactive and Artificially Produced What's in a name? Named after the scientist Lise Meitner. Say what? Meitnerium is pronounced as met-NEAR-ee-um. History and Uses: Meitnerium was first produced by Peter Armbruster, Gottfried Münzenber and their team working at the Gesellschaft für Schwerionenforschung in Darmstadt, Germany in 1982. They bombarded atoms of bismuth-209 with ions of iron-58 with a device known as a linear accelerator. This produced atoms of meitnerium-266, an isotope with a half-life of about 3.8 milliseconds (0.0038 seconds), and a free neutron. Meitnerium's most stable isotope, meitnerium-278, has a half-life of about 11 seconds. It decays into bohrium-274 through alpha decay. <span style="font-family: Arial,Helvetica,sans-serif;">Since only small amounts of meitnerium have ever been produced, it currently has no uses outside of basic scientific research. <span style="font-family: Arial,Helvetica,sans-serif;">Estimated Crustal Abundance: Not Applicable <span style="font-family: Arial,Helvetica,sans-serif;">Estimated Oceanic Abundance: Not Applicable <span style="font-family: Arial,Helvetica,sans-serif;">Number of Stable Isotopes: 0 <span style="font-family: Arial,Helvetica,sans-serif;">Ionization Energy: Unknown <span style="font-family: Arial,Helvetica,sans-serif;">Oxidation State: Unknown

<span style="font-family: Arial,Helvetica,sans-serif;">Basic Information
<span style="font-family: Arial,Helvetica,sans-serif;">Name: Meitnerium Symbol: Mt Atomic Number: 109 Atomic Mass: (266.0) amu Melting Point: Unknown Boiling Point: Unknown Number of Protons/Electrons: 109 Number of Neutrons: 157 Classification: Transition Metal Crystal Structure: Unknown Density @ 293 K: Unknown Color: Unknown Other Names: Unnilennium (Une), Meitnerium (Mt), Meitnerium (Mt)

<span style="font-family: Arial,Helvetica,sans-serif;">Atomic Structure
<span style="font-family: Arial,Helvetica,sans-serif;">First Energy Level: Second Energy Level: Third Energy Level: Fourth Energy Level: Fifth Energy Level: Sixth Energy Level: Seventh Energy Level: ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">[[image:http://www.chemicalelements.com/bohr/b0109.gif]] ||  || <span style="font-family: Arial,Helvetica,sans-serif;">Number of Energy Levels: 7

<span style="font-family: Arial,Helvetica,sans-serif;">Isotopes

 * <span style="font-family: Arial,Helvetica,sans-serif;">Isotope || <span style="font-family: Arial,Helvetica,sans-serif;">Half Life ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Mt-226 || <span style="font-family: Arial,Helvetica,sans-serif;">3.4 milliseconds ||

<span style="font-family: Arial,Helvetica,sans-serif;">Facts
<span style="font-family: Arial,Helvetica,sans-serif;">Date of Discovery: 1982 Discoverer: Heavy Ion Research Laboratory Name Origin: After Lise Meitner (Austrian physicist) Uses: No uses known Obtained From: Man-made

<span style="font-family: Arial,Helvetica,sans-serif;">Harmful effects: Meitnerium is harmful due to its radioactivity. <span style="font-family: Arial,Helvetica,sans-serif;">Characteristics: Meitnerium is a synthetic, radioactive metal and has only been produced in tiny amounts. <span style="font-family: Arial,Helvetica,sans-serif;">History and Uses:

<span style="font-family: Arial,Helvetica,sans-serif;">Meitnerium was first produced by Peter Armbruster, Gottfried Münzenber and their team working in Darmstadt, Germany in 1982. They bombarded atoms of [|bismuth]-209 with ions of [|iron]-58 with a device known as a linear accelerator. This produced atoms of meitnerium-266, an [|isotope] with a [|half-life] of about 3.8 milliseconds (0.0038 seconds), and a free [|neutron].

<span style="font-family: Arial,Helvetica,sans-serif;">Meitnerium's most stable [|isotope], meitnerium-278, has a [|half-life] of about 11 seconds. It decays into [|bohrium]-274 through[|alpha decay].

<span style="font-family: Arial,Helvetica,sans-serif;">Since only small amounts of meitnerium have ever been produced, it currently has no uses outside of basic scientific research.

<span style="font-family: Arial,Helvetica,sans-serif;">Chemical
<span style="font-family: Arial,Helvetica,sans-serif;">Unambiguous determination of chemical character of meitnerium has yet to have been established due to two reasons: lack of sufficiently long-lived isotope, and a limited amount of likely volatile compounds that could be studies on a very small scale. However, the IrF6fluoride is volatile above 60 ºC and therefore the identical compound of meitnerium might also be sufficiently volatile. However, since[|element 112] has been shown to be a transition metal, it is expected that all the elements in the 104–111 range would form a fourth transition metal series, with meitnerium as part of the [|platinum group metals].[|[9]] Only extrapolated chemical properties are available for meitnerium.

<span style="font-family: Arial,Helvetica,sans-serif;">Oxidation states
<span style="font-family: Arial,Helvetica,sans-serif;">Meitnerium is projected to be the sixth member of the 6d series of transition metals and the heaviest member of group 9 in the Periodic Table, below [|cobalt], [|rhodium] and [|iridium]. This group of [|transition metals] is the first to show lower oxidation states and the +9 state is not known. The latter two members of the group show a maximum oxidation state of +6, whilst the most stable states are +4 and +3 for iridium and +3 for rhodium. Meitnerium is therefore expected to form a stable +3 state but may also portray stable +4 and +6 states.[[|citation needed]]The oxidation state +9 might also be possible for meitnerium.[|[25]]

<span style="font-family: Arial,Helvetica,sans-serif;">Chemistry
<span style="font-family: Arial,Helvetica,sans-serif;">The +VI state in group 9 is known only for the fluorides which are formed by direct reaction. Therefore, meitnerium should form a hexafluoride, MtF6. This fluoride is expected to be more stable than iridium(VI) fluoride, as the +6 state becomes more stable as the group is descended.[[|citation needed]] <span style="font-family: Arial,Helvetica,sans-serif;">In combination with oxygen, rhodium forms Rh2O3 whereas iridium is oxidised to the +4 state in IrO2. Meitnerium may therefore show a dioxide, MtO2, if eka-iridium reactivity is shown.[[|citation needed]] <span style="font-family: Arial,Helvetica,sans-serif;">The +3 state in group 9 is common in the trihalides (except fluorides) formed by direct reaction with [|halogens]. Meitnerium should therefore form MtCl3, MtBr3 and MtI3 in an analogous manner to iridium.[[|citation needed]] The tetrahalides have been predicted to have similar stabilities as those of iridium.[|[26]] <span style="font-family: Arial,Helvetica,sans-serif;">Theoreticians have predicted the covalent radius of meitnerium to be 6 to 10 pm larger than that of iridium.[|[27]] For example, the Mt–O bond distance is expected to be around 1.9 Å.[|[28]]

<span style="font-family: Arial,Helvetica,sans-serif;">Physical and atomic
<span style="font-family: Arial,Helvetica,sans-serif;">Meitnerium is expected to be a solid under normal conditions and assume a face-centered-cubic [|crystal structure].[|[1]] <span style="font-family: Arial,Helvetica,sans-serif;">Mt should be a very heavy metal with a [|density] around 30 g/cm3 (Co: 8.9, Rh: 12.5, Ir: 22.5) and a high melting point around 2600–2900°C (Co: 1480, Rh: 1966, Ir: 2454). It should be very corrosion-resistant; even more so than Ir which is currently the most corrosion-resistant metal known.[[|citation needed]] <span style="font-family: Arial,Helvetica,sans-serif;">The atomic electronic configuration is predicted to be [Rn] 5f14 6d7 7s2.[|[28]]