Write the balanced nuclear equation for the synthesis of roentgenium

There are seven known isotopes of the element: 272, 274 and 278-282. The longest lived is isotope 281 which has a half-life of 22.8 seconds. In 1986, physicists at the Russian Joint Institute for Nuclear Research (JINR), bombarded bismuth with nickel hoping to make element 111, but they failed to detect any atoms of element 111. In 1994, a team led by Peter Armbruster and Gottfred Munzenberg at the German Geselleschaft für Schwerionenforschung (GSI), were successful when they bombarded bismuth with nickel and they obtained few atoms of isotope 272. It had a half-life of 1.5 milliseconds.

Atomic radius, non-bonded
Half of the distance between two unbonded atoms of the same element when the electrostatic forces are balanced. These values were determined using several different methods.
Covalent radius
Half of the distance between two atoms within a single covalent bond. Values are given for typical oxidation number and coordination.
Electron affinity
The energy released when an electron is added to the neutral atom and a negative ion is formed.
Electronegativity (Pauling scale)
The tendency of an atom to attract electrons towards itself, expressed on a relative scale.
First ionisation energy
The minimum energy required to remove an electron from a neutral atom in its ground state.

Atomic data

Atomic data

Glossary
Common oxidation states The oxidation state of an atom is a measure of the degree of oxidation of an atom. It is defined as being the charge that an atom would have if all bonds were ionic. Uncombined elements have an oxidation state of 0. The sum of the oxidation states within a compound or ion must equal the overall charge.
Isotopes Atoms of the same element with different numbers of neutrons.
Key for isotopes

Oxidation states and isotopes

Oxidation states and isotopes

Glossary Data for this section been provided by the British Geological Survey .
Relative supply risk An integrated supply risk index from 1 (very low risk) to 10 (very high risk). This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores.
Crustal abundance (ppm) The number of atoms of the element per 1 million atoms of the Earth’s crust.
Recycling rate The percentage of a commodity which is recycled. A higher recycling rate may reduce risk to supply.
Substitutability The availability of suitable substitutes for a given commodity.
High = substitution not possible or very difficult.
Medium = substitution is possible but there may be an economic and/or performance impact
Low = substitution is possible with little or no economic and/or performance impact

Production concentration The percentage of an element produced in the top producing country. The higher the value, the larger risk there is to supply.
Reserve distribution The percentage of the world reserves located in the country with the largest reserves. The higher the value, the larger risk there is to supply.
Political stability of top producer A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators.
Political stability of top reserve holder A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators.

Glossary
Specific heat capacity (J kg −1 K −1 ) Specific heat capacity is the amount of energy needed to change the temperature of a kilogram of a substance by 1 K.
Young's modulus A measure of the stiffness of a substance. It provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain.
Shear modulus A measure of how difficult it is to deform a material. It is given by the ratio of the shear stress to the shear strain.
Bulk modulus A measure of how difficult it is to compress a substance. It is given by the ratio of the pressure on a body to the fractional decrease in volume.
Vapour pressure A measure of the propensity of a substance to evaporate. It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system.

Pressure and temperature data – advanced

Pressure and temperature data – advanced

Podcasts

Podcasts

Chemistry in its element: roentgenium

You're listening to Chemistry in its element brought to you by Chemistry World, the magazine of the Royal Society of Chemistry.

This week an element that needs just the right conditions in order to get a successful collision. Here's Simon Cotton:

I used to be able to go into my chemistry lab, look the pupils in the eye, and say 'U-U-U'. And they would say 'What have I done, Sir?' 'You've done nothing wrong' I would reply, 'I am talking about Element 111, unununium, symbol Uuu'.

So I was a bit sad when in 2004 a joint working party of the International Union of Pure and Applied Chemistry and International Union of Pure and Applied Physics recommended that the name of element 111 be changed to roentgenium, symbol Rg.

Roentgenium was in fact discovered 10 years earlier on December 8, 1994, by a team of 13 nuclear physicists working at the Gesellschaft für Schwerionenforschung at Darmstadt in Germany carried out an experiment, bombarding a target of 209Bi with 64Ni ions. The idea was to make the nickel ions penetrate the bismuth nucleus, so that the two nuclei would fuse together, making a bigger atom. The energy of the collision had to be carefully controlled, because if the nickel ions were not going fast enough, they could not overcome the repulsion between the two positive nuclei, would just fly off the bismuth on contact. However, if the nickel ions had too much energy, the resulting 'compound nucleus' would have so much excess energy that it could undergo fission and just fall apart. The trick was, like Goldilocks' porridge, to be 'just right', so that the fusion of the nuclei would occur, just.

Successful collisions would not occur very often, as most of an atom is empty space. The scientists were however able to observe three successful collisions, forming atoms of atomic number 111 and mass 272. They were very short-lived, with a half-life of around 1 ½ milliseconds. The new atoms were identified by following what happened to them when they decayed - they underwent alpha decay successively forming atoms of elements 109, 107, 105 and 103. In further experiments carried out in 2000, the team carried out more bombardments and observed another three more atoms of element 111. This time they followed the decay chains even further, right down to mendelevium-252, element 101.

The discovery of this new element was first announced in a paper published early in 1995. It was given a temporary name of unununium, derived from its atomic number, and the symbol Uuu. No permanent name was assigned to element 111, as independent confimation of its existence was needed, and this did not happen until 2003, when a team at the RIKEN Linear Accelerator facility in Japan made 14 atoms of this isotope. The workers at Darmstadt were then given the honor of proposing proposed the name roentgenium, in recognition of Wilhelm Conrad Roentgen, who discovered X-rays in 1895.

No one knows for sure what roentgenium looks like, but it has been placed under copper, silver and gold in the Periodic Table. Theoretical chemists have had fun predicting its properties, and they think that if anyone ever sees any roentgenium metal, it is likely to be silver in colour and it will be very unreactive. Its chemistry is predicted to involve the +3 and +5 oxidation states.

When scientists made element 115 back in 2004, they identified in its decay chain a roentgenium isotope of mass 280 with a half life of about 3.6 seconds. So if it can be made directly, there is the possibility of real chemical reactions being studied.

So, ladies and gentlemen, that is roentgenium, which looks like being a very precious metal, albeit only for a few seconds.

So blink and you may just miss the magic. That was Uppingham School's Simon Cotton with the speedy yet precise chemistry of roentgenium. Now next week we've got a two-faced element.

Chlorine is what you might describe as a Jekyll and Hyde element; it is the friend of the synthetic chemist and has found a use in a number of 'nice' applications such as the disinfecting of drinking water and keeping our swimming pools clean. It also has an unpleasant side, being the first chemical warfare agent and taking some of the blame for the depletion of the Earth's ozone layer.

So is it friend or is it foe? Join Bristol University's Tim Harrison to find out in next week's Chemistry in its element. Until then I'm Meera Senthilingam and thank you for listening.

Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists.com. There's more information and other episodes of Chemistry in its element on our website at chemistryworld.org/elements.

Video

Video

Resources

Resources

Terms & Conditions
Images © Murray Robertson 1999-2011
Text © The Royal Society of Chemistry 1999-2011

Welcome to "A Visual Interpretation of The Table of Elements", the most striking version of the periodic table on the web. This Site has been carefully prepared for your visit, and we ask you to honour and agree to the following terms and conditions when using this Site.
Copyright of and ownership in the Images reside with Murray Robertson. The RSC has been granted the sole and exclusive right and licence to produce, publish and further license the Images.
The RSC maintains this Site for your information, education, communication, and personal entertainment. You may browse, download or print out one copy of the material displayed on the Site for your personal, non-commercial, non-public use, but you must retain all copyright and other proprietary notices contained on the materials. You may not further copy, alter, distribute or otherwise use any of the materials from this Site without the advance, written consent of the RSC. The images may not be posted on any website, shared in any disc library, image storage mechanism, network system or similar arrangement. Pornographic, defamatory, libellous, scandalous, fraudulent, immoral, infringing or otherwise unlawful use of the Images is, of course, prohibited.
If you wish to use the Images in a manner not permitted by these terms and conditions please contact the Publishing Services Department by email. If you are in any doubt, please ask.
Commercial use of the Images will be charged at a rate based on the particular use, prices on application. In such cases we would ask you to sign a Visual Elements licence agreement, tailored to the specific use you propose.
The RSC makes no representations whatsoever about the suitability of the information contained in the documents and related graphics published on this Site for any purpose. All such documents and related graphics are provided "as is" without any representation or endorsement made and warranty of any kind, whether expressed or implied, including but not limited to the implied warranties of fitness for a particular purpose, non-infringement, compatibility, security and accuracy.
In no event shall the RSC be liable for any damages including, without limitation, indirect or consequential damages, or any damages whatsoever arising from use or loss of use, data or profits, whether in action of contract, negligence or other tortious action, arising out of or in connection with the use of the material available from this Site. Nor shall the RSC be in any event liable for any damage to your computer equipment or software which may occur on account of your access to or use of the Site, or your downloading of materials, data, text, software, or images from the Site, whether caused by a virus, bug or otherwise.
We hope that you enjoy your visit to this Site. We welcome your feedback.