nobelium

Nobelium is a synthetic chemical element with the symbol No and atomic number 102. It is a member of the actinide series and is highly radioactive. No is not found in nature and has been produced only in minute quantities in particle accelerators or nuclear reactors. The most stable known isotopes have very short half-lives, and practical samples are difficult to obtain.

Discovery and name

Nobelium was first reported in 1957 by collaborations at the Joint Institute for Nuclear Research in Dubna and at Lawrence Berkeley National Laboratory in the United States. The element was named nobelium in honor of the Swedish inventor and chemist Alfred Nobel. The name was officially adopted by IUPAC in 1958.

Production

Nobelium is produced by nuclear reactions that involve bombarding heavy actinide targets, such as curium or californium, with light ions in a particle accelerator. The resulting nuclides undergo rapid radioactive decay, making handling and study require specialized facilities and techniques. Because of the short half-lives and tiny production yields, chemical studies are highly challenging.

Isotopes and properties

A number of nobelium isotopes have been synthesized, with mass numbers typically in the 250–260 range. All known isotopes are radioactive, decaying by alpha emission or spontaneous fission. The element is expected to exhibit multiple oxidation states in theory, with +3 commonly discussed for late actinides; detailed aqueous and complex chemistry is limited by radioactivity and short lifetimes.

Uses and safety

Nobelium has no commercial applications and is studied primarily for basic nuclear and chemical research, including investigations into the chemistry of transactinide elements and relativistic effects in heavy atoms. Handling requires specialized containment, remote manipulation, and extensive radiological controls due to extreme radioactivity.