Named after eminent physicist Lise Meitner, Meitnerium (Mt) was first discovered synthetically by Peter Armbruster and Gottfried Münzenber in Darmstadt, Germany. Working at the GSI Helmholtz Centre for Heavy Ion Research Laboratory, the pair came up with the element by bombarding Bismuth-209 with an accelerated Iron-58 nucleus.
Meitnerium has a few isotopes, out of which Meitnerium-278 has the longest half-life of 4.5 seconds.
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History of Meitnerium
Mt element has a very interesting history associated with it. The element is not a naturally occurring one. It was synthesised under laboratory conditions.
The team of scientists first accelerated several nuclei of iron-58 and hit them to a target of bismuth-209. After this experiment, they were presented with a single atom of Meitnerium-266.
The chemical reaction detected was as follows:
20983Bi + 5826Fe → 266109Mt + n
The reaction and the product thus produced was accepted by the scientific community three years later at the Joint Institute for Nuclear Research (Russia).
Naming of the Element
Putting to use Mendeleev’s nomenclature practices, the element was supposed to be named as eka-iridium. Then in 1979, after IUPAC published their own set of rules to name elements and compounds, the element was provided with a makeshift name of unnilennium. But neither of these names were popularly used by textbooks and other communities. Scientists, for most of their experiments, called it 'element 109’ or E109 or even only 109.
During that decade, a popular debate ensued among chemists regarding the naming of elements of atomic numbers between 104 and 109. It was at this time that the GSI team proposed the name Meitnerium (Mt) in September 1992 to honour the famous Austrian physicist Lise Meitner, who also discovered protactinium along with Otto Hahn and was one of the pioneers for nuclear fission. The name was then accepted by the IUPAC and made official in 1997.
Did You Know?
Meitnerium is the only compound other than Curium, which has been named after a real person and not a mythological character. Curium was named after scientists Marie and Pierre Curie.
Isotopes of the Element
Since the element is not naturally occurring, there are no stable naturally occurring isotopes of it too. Most of its isotopes have been synthesised inside laboratories and are radioactive. They were done mostly by fusing two of the same atoms or found when heavier atoms were decaying after fission. Till date, there are eight different isotopes of Mt with masses 266, 268, 270 and 274-278.
Owing to the laboratory invention procedure, almost all isotopes of the compound are radioactive and unstable. It has been seen that compounds with heavier nuclei mass are more stable.
The same goes for Meitnerium too. The most stable isotope, 278Mt, is the heaviest know yet and has a half-life of 4.5 seconds. An even heavier, unconfirmed isotope 282Mt, has a longer half-life of 67 seconds. But other than these, all other isotopes of Mt have a half-life in fractions of seconds.
The Table Below Lists All The Isotopes of Mt and Other Relevant Information Regarding All of Them.
Meitnerium assumes a cubic crystal structure, and similar to iridium. It is face-centred and is predicted to be solid at room temperature.
It is supposed to be exceptionally heavy, with a density of 37.4 g/cm3.
With this high density, it is expected to be the second most dense of all known 118 elements. It is second only to Hassium which has a density of 41 gm/cm3.
The Lanthanide and Actinide contractions, as well as its very high atomic weight, could be some of the factor contributing to its exceptionally high density.
It is also supposed to have paramagnetic properties and a very quick rate of decay.
Its covalent radius has been predicted to be 6-10 pm larger than iridium.
The atomic radius of Meitnerium is around 128 pm.
Atomic and Physical Properties
Meitnerium Chemical Properties and Uses
This rare element and its parent elements show a remarkable rate of decay. Owing to this, the production of Meitnerium is very limited and costly. Its exact properties remain unknown whatsoever, but some predictions state the following probable properties:
It is the 7th member, belonging to the 6d series of transition metals.
As is known, copernicium or element number 112 is a metal belonging to Group 12. It is predicted that all elements from number 104 to 111 would exhibit the properties of fourth transition metal. Meitnerium too forms a part of this series and a component of the platinum group metals.
Scientific research posits the fact that it might resemble Group 9 elements such as cobalt, iridium and rhodium in its properties.
Meitnerium also shares similarities with iridium in terms of ionic and atomic radii, as well as ionisation potentials.
Not much is known about its chemical properties. It is expected to be a noble metal, by a study of its characteristics and could resemble silver in terms of how noble it is.
Predictions about this element's oxidation states list +6, +1 and +3 as the most stable.
In aqueous solutions, +3 is among the most stable oxidation states.
Tetrahalides of this element also show similarities in stability to iridium, making way for a possible +4 state.
The following table illustrates some known properties of Meitnerium.
Properties of Meitnerium
Activity: Ask your teacher for some more Mt periodic table properties as well as important pointers to know. Learn them and discuss them with friends.
The element’s immensely high rate of decay and relativistic effects has made it almost impossible to produce in large amounts. Presently, it is only manufactured in sparse quantities for scientific research.
Experimental Chemistry on Meitnerium
Very few elements are there in the periodic table which has so little chemical or physical properties known to us, and Meitnerium is one of them. Because of the very short-lived radioactive isotopes and other volatile compounds which decay into other atoms faster than needed to be experimented upon, Mt has extremely limited functions. Some of its chemical compounds which are sufficiently volatile include Meitnerium hexafluoride (MtF6) and another homologue of the same compound, iridium hexafluoride (IrF6).
Though students may debate that the half-life of 278Mt is 4.5 seconds and that is enough to carry experiments on, another problem comes along with it. A steady scientific experiment expected to produce any tangible result needs a huge number of atoms of the same element. But till now, only ten atoms of Meitnerium have been produced at scale. Due to all these factors, Mt has not received the same research enthusiasm as had some of its other heavier counterparts like livermorium and copernicium.
When seaborgium hexacarbonyl was successfully produced in 2014, there arrived a hope in the scientific sphere that formation of carbonyl compounds can be useful for studying such heavy elements.
But due to similar reasons stated above, such studies were not possible for Mt, though 278Mt and 276Mt live long enough to perform experiments and can be produced from 294Ts and 288Mc.
Another isotope, 270Mt, observed in the decay procedure of 278Nh, has a half-life of 0.69 seconds, which is again sufficient for experimentation. But even for that, a direct production procedure needs to be formulated, which has not yet been done.
So, this was all regarding Meitnerium and its chemical and physical properties. If you want to learn more about Meitnerium or its other heavier counterparts, visit Vedantu’s website or download our mobile app today. We host numerous such tutorials and guides on several topics related to your exams. See you there!
FAQs on Meitnerium
1. What is Meitnerium and what is its atomic number?
Meitnerium is a synthetic, superheavy chemical element with the symbol Mt and atomic number 109. As a synthetic element, it does not occur naturally on Earth and can only be created in a laboratory environment through complex nuclear reactions. It is classified as a transition metal.
2. What are some of the key predicted properties of Meitnerium?
Since only a few atoms of Meitnerium have ever been produced, its properties are based on theoretical predictions. Key predicted properties include:
- State: Expected to be a solid at room temperature.
- Density: Predicted to be extremely high, around 37.4 g/cm³, which would make it the second-densest known element after Hassium.
- Appearance: Likely a silvery-white or greyish metal, similar to other platinum group metals.
- Structure: Assumed to have a face-centred cubic crystal structure, similar to iridium.
3. After whom is Meitnerium (element 109) named?
Meitnerium is named in honour of Lise Meitner, an Austrian-Swedish physicist renowned for her work on radioactivity and nuclear physics. She was a key member of the team that discovered nuclear fission, a monumental scientific breakthrough. The naming of element 109 was a posthumous tribute to her fundamental contributions to science.
4. Why is Meitnerium expected to share chemical properties with elements like iridium and cobalt?
Meitnerium is located in Group 9 and Period 7 of the periodic table, placing it directly below cobalt, rhodium, and iridium. According to the periodic law, elements within the same group typically have similar valence electron configurations, which dictates their chemical behaviour. Therefore, Meitnerium is predicted to exhibit properties and stable oxidation states (such as +3, +1, and +6) that are similar to its lighter homologue, iridium.
5. Why is it extremely difficult to determine the uses and experimental chemistry of Meitnerium?
The study and application of Meitnerium are severely restricted by two major challenges:
- Extreme Instability: Meitnerium's isotopes are highly radioactive and possess very short half-lives, often decaying into different elements within seconds. This rapid decay provides an insufficient timeframe for conducting meaningful chemical experiments.
- Production Scarcity: Creating Meitnerium requires bombarding heavy element targets with ion beams in a particle accelerator. This method is incredibly inefficient and expensive, yielding only a few atoms at a time. Without a measurable quantity, its bulk properties and potential uses remain purely theoretical.
6. What is the predicted electron configuration for Meitnerium?
The predicted or expected electron configuration for Meitnerium (Mt) is [Rn] 5f¹⁴ 6d⁷ 7s². This configuration places it within the 6d series of transition metals and is consistent with its position in Group 9 of the periodic table, providing the basis for predicting its chemical characteristics.
7. How do relativistic effects impact the characteristics of a superheavy element like Meitnerium?
In superheavy elements like Meitnerium, the immense positive charge of the nucleus (109 protons) accelerates inner-shell electrons to speeds close to the speed of light. This triggers relativistic effects, causing the s and p orbitals to contract and move closer to the nucleus, while the d and f orbitals expand. This phenomenon significantly alters the element's ionisation energies, atomic radius, and oxidation states, causing its properties to deviate from the simple periodic trends observed in lighter elements.
