365: Chemistry for Life
DAY 80

Darleane Hoffman and Plutonium

Plutonium named: In 1942, a secret report was submitted suggesting the name "plutonium" for artificial element 94 since it followed neptunium and uranium (elements 93 & 92). In 1971, Darleane Christian Hoffman discovered small amounts of plutonium in a rock formation.

Credit: iStock

Over the course of her career Darleane Hoffman (b. 1926) has chased some of the most elusive forms of matter—the heavy elements. These elements, which include plutonium, are hard to produce and exist for very short periods of time, yet Hoffman has succeeded in capturing and analyzing them. In studying these fugitive elements, she has made important discoveries about the nature of fission, the atomic process at the heart of nuclear power.

Hoffman became known for a number of important achievements. For years, scientists believed that transuranium elements did not occur in nature, but in 1971 Hoffman published her discovery of small amounts of a plutonium isotope (plutonium-244) in a rock formation that was several billion years old. Hoffman also carried out a rare study of the chemistry of the element hahnium, also called dubnium. The study was rare because transuranium elements are so radioactive that they quickly decay before they can be studied.

Visit Chemistry in History to learn more about Darleane Hoffman and plutonium.

Excerpted with permission, Chemical Heritage Foundation
www.chemheritage.org