Skip to Main Content

Americium (Am): Actinides

Americium (Am)

What is Americium?

Americium (Am), synthetic chemical element (atomic number 95) of the actinoid series of the periodic table. Unknown in nature, americium (as the isotope americium-241) was artificially produced from plutonium-239 (atomic number 94) in 1944 by American chemists Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, and Albert Ghiorso in a nuclear reactor. It was the fourth transuranium element to be discovered (curium, atomic number 96, was discovered a few months previously). The element was named after the United States of America. The metal is silvery white and tarnishes slowly in dry air at room temperature. Continue reading from Encyclopedia Britannica 

The History

This element was in fact discovered after curium, the element which follows it in the periodic table. However, it did once exist on Earth having been produced for millions of years in natural nuclear reactors in Oklo, Gabon. These ceased to function a billion years ago, and as the longest lived isotope is americium-247, with a half-life of 7370 years, none has survived to the present day. Americium was first made late in 1944 at the University of Chicago by a team which included Glenn Seaborg, Ralph James, Leon Morgan, and Albert Ghiorso. The americium was produced by bombarding plutonium with neutrons in a nuclear reactor. This produced isotope americium-241, which has a half-life of 432 years. Continue reading from Royal Society of Chemistry 

Americium Facts

Americium is primarily produced in nuclear reactors via the bombardment of plutonium with neutrons. According to the World Nuclear Association, smoke detectors that use americium are popular in homes and are sensitive to the presence of smoke or heat. The discoveries of americium and curium were announced in late 1945 by Glenn Seaborg on the live radio show Quiz Kids. The announcement was meant to have occurred five days later at a national meeting of the American Chemical Society. Americium is a highly radioactive element that can be dangerous when handled incorrectly and can cause severe illnesses. Continue reading from Live Science

Chart of Elemental Properties for Americium

Watch a Video on Americium

Check out our Science Database or a Science Book from our Collection

Link to Science Reference Center Database
Link to Elemntal by Tim James in the catalog
Link to The Periodic Table: A Very Short Introduction by Eric Scerri in the catalog
Link to Eureka!: Discovering Your Inner Scientist by Chad Orzel in the catalog
Link to Absolutely small : how quantum theory explains our everyday world by Michael Fayer in the catlog
link to Seven elements that changed the world : an adventure of ingenuity and discovery by John Brown in the catalog
Link to From Arsenic to Zirconium : poems and surprising facts about the elements by Peter Devern in the catalog
link to The elements : a visual exploration of every known atom in the universe by Theodore Gray in the catalog
link to Chemistry demystified by Linda Williams in the catalog
link to 10 women who changed science, and the world by Catherine Whitlock in the catalog

Return to the Periodic Table of Elements Resource Guide Series