An Overview about the Chemical Element Nobelium


Symbol: No

Atomic Number: 102

Atomic Mass: 259.0 amu atomic mass units

Melting Point: 827 C (1100 K, 1520 F)

Boiling Point: Unknown

Number of Protons: 102

Number of Electrons: 102

Number of Neutrons: 157

Classification: Rare Earth (Man made)

Crystal Structure: Unknown

Density @ 293 K: Unknown

Color: Unknown

The first alleged discovery of element 102 was made by scientists at the Nobel Institute of Physics in Stockholm Sweden. They bombarded a target of curium-244 with ions of carbon-13. They claimed to have produced an isotope with a half-life of ten minutes. This group put forward the name nobelium for the element in honor of the Swedish scientist Alfred Nobel, discoverer of dynamite and the founder of the Nobel Prize.

In 1958 scientists at the Lawrence Radiation Laboratory (now known as the Lawrence Berkeley Laboratory) in Berkeley, California, USA attempted to repeat this experiment but failed to produce any of the element using the same procedure as the Swedish group. However in the same year this group of Albert Ghiorso, Glenn T. Seaborg, Torborn Sikkeland and John R. Walton managed to produce an isotope of element 102 with a half-life of three seconds. This was made by using a target of curium-246 and ions of carbon-12.

Also in 1958 a team of Russian scientists at the Joint Institute for Nuclear Research in Dubna, Russia confirmed the American teams’ discovery. This Russian team was also unable to produce any atoms of the element by the same method as that used at the Nobel Institute.

With the claim by the Nobel Institute in doubt credit for the discovery of element 102 was given to the Lawrence Radiation Laboratory group by the International Union of Pure and Applied Chemistry (IUPAC). This group opted to keep the name nobelium along with the symbol No for this element.

The isotope found by the Americans and confirmed by the Russians was nobelium-254. A number of other isotopes have been produced with mass numbers ranging from 249 to 262. To date the isotope claimed by the Swedish group has not been reproduced.

Nobelium-259 is the most stable isotope of the element produced. This isotope has a half-life of fifty three minutes. It decays by either alpha decay to form fermium-255 or by electron capture to form mendelevium-259.

Only a small number of atoms of this element have ever been produced. At present most of its bulk properties are unknown. From its position in the actinide group of elements it is probable that it is a metallic element and gray or white in color.

With such a small number of atoms available it is unlikely that any use, other than scientific research, will ever be found for the element nobelium.