Nobelium (No)

• Element Symbol: No
• Atomic Number: 102
• Atomic Mass: 259
• Group # in Periodic Table: n/a
• Group Name: Actinides
• Period in Periodic Table: 7
• Block of Periodic Table: f-block
• Discovered by: Joint Institute for Nuclear Research, Dubna, Soviet Union (1966)

Nobelium is a synthetic, radioactive metallic element whose symbol is No and whose atomic number is 102. Like all other elements with an atomic number over 100, nobelium can only be made in particle accelerators. This process involves bombarding lighter elements with charged particles. Nobelium is the tenth transuranic element. These unstable elements are the ones that have atomic numbers greater than 92, the atomic number of uranium. Nobelium is also the penultimate member of the actinide series. This series consists of the fifteen elements with atomic numbers from 89 to 103—actinium through lawrencium. Nobelium is synthetic and therefore does not occur in nature. Because it has no known practical uses, it is only used for theoretical chemistry and nuclear research.

This element, named in honor of Alfred Nobel, was first officially synthesized by research scientists in 1966 at the Joint Institute for Nuclear Research in Dubna, Soviet Union (now Russia), led by Georgy Flerov. However, two other research institutes claimed to have discovered nobelium first. The first one, the Swedish Nobel Institute for Physics, claimed it had produced nobelium in 1957. The research scientists there believed that they had successfully synthesized element 102 and even named it "nobelium" after their founder. However, after further testing, they retracted the discovery. The second institute was the University of California, Berkeley, where a team led by Albert Ghiorso claimed to have produced element 102 in 1958. This conflict over just which team had discovered nobelium was resolved by the International Union of Pure and Applied Chemistry (IUPAC) in 1992 after it had conducted extensive investigations of the claims. The IUPAC ruled that the discovery was most likely to have occurred in Dubna in 1966.

Physical Properties

Nobelium can be found in the periodic table between two of its fellow actinides, the elements mendelevium and lawrencium. The actinides are all group 7 elements. Due to the fact that nobelium is synthetic, nobelium metal has never been prepared in bulk quantities. Bulk preparation of any of the synthetic elements is currently impossible. Despite this fact, a couple of predictions have been made regarding what these physical properties might be. First, it is predicted to be solid in its standard state at 298 kelvins (K). Second, its predicted melting point is 827 degrees Celsius (°C). Its boiling point, density, specific heat, thermal conductivity, and electrical conductivity are unknown. Experiments are still being conducted to determine just what exactly these physical properties might be.

Chemical Properties

Just like its physical properties, nobelium’s chemical properties have not been completely identified yet. Decades of experimentation have thus far determined that nobelium has two distinct oxidation states, +3 and +2, with the latter being the more stable one. This makes nobelium distinct from the other actinides, for which the +3 oxidation state is the more stable one. Since its +2 oxidation state is more stable, nobelium could theoretically react with chlorine and the alkaline earth metals calcium and strontium.

Twelve isotopes are currently known, with mass numbers ranging from 250 through 260, plus 262. Every one of them is unstable and therefore radioactive. Of these twelve, the longest lived is nobelium-259, which has a half-life of fifty-eight minutes. The others have half-lives ranging from three minutes (nobelium-255) to just a few milliseconds (nobelium-258).

Applications

Nobelium is a synthetic element. Therefore, it is not found anywhere in nature. Instead, nobelium is created in a lab using nuclear bombardment. Specifically, nobelium is made by bombarding curium with carbon in a device called a cyclotron. Since this process is so complicated, nobelium has only been produced in miniscule quantities.

Due to the fact that creating it is so difficult, nobelium is only used for theoretical chemistry and nuclear research. Also, since it is extremely radioactive—and therefore toxic—nobelium has absolutely no potential biological uses. So just like the other synthetic actinide metals, nobelium has no useful applications.

Like mendelevium, nobelium was named after a famous scientist—in this case, Alfred Nobel, the Swedish physicist who established the Nobel Prize. Nobel may have been immortalized as a result of the fact that he had an element named for him, but element 102 has a half-life of only 12.6 hours and absolutely no applications. Just like mendelevium, named for Dmitri Mendeleev, Alfred Nobel’s element is relatively undistinguished.

Bibliography

Cottrell, T. L. The Strengths of Chemical Bonds. New York: Academic, 1954. Print.

Coursey, J. S., et al. Atomic Weights and Isotopic Compositions with Relative Atomic Masses. NIST Physical Measurement Laboratory. Natl. Inst. of Standards and Technology, 30 Sept. 2015. Web. 13 Nov. 2015.

Haynes, William M., ed. CRC Handbook of Chemistry and Physics. 95th ed. Boca Raton: CRC, 2014. Print.

Kaye & Laby Tables of Physical & Chemical Constants. Natl. Physical Laboratory, 2015. Web. 25 Sept. 2015.

Silva, Robert J. "Fermium, Mendelevium, Nobelium, and Lawrencium." The Chemistry of the Actinide and Transactinide Elements. Ed. Lester R. Morss, Norman M. Edelstein, and Jean Fuger. 4th ed. Vol. 3. Dordrecht: Springer, 2010. 1621–51. Print.

"Technical Data for Nobelium." The Photographic Periodic Table of the Elements. Element Collection, n.d. Web. 25 Sept. 2015.