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Americium-Discovery, Properties, And Applications

October 15, 2023
written by Adeel Abbas

Americium is a radioactive chemical element with the symbol Am and atomic number 95. It is a synthetic element that was first produced in 1944 by Glenn T. Seaborg, Ralph A. James, and Albert Ghiorso at the University of California, Berkeley.

Atomic number95
Relative atomic mass (Ar)Block in the periodic table
Standard stateSolid at 298 K
AppearanceSilvery white
Group in periodic table
Group nameActinoid
Group in the periodic table7 (actinoid)
Period in the periodic tablef
Shell structure2.
CAS Registry7440-35-9
image of Americium element

Physical Properties

  • Americium is a silvery-white metal that slowly tarnishes in air.
  • It is a dense metal with a melting point of 1173 K and a boiling point of 2607 K.
  • Americium is paramagnetic, meaning that it is weakly attracted to a magnetic field.

Chemical Properties

  • Americium is a highly reactive metal that reacts with oxygen, water vapor, and acids.
  • It is a strong alpha emitter and has several isotopes, the most stable of which is Americium-243.
  • Americium can be used as a fuel in some types of nuclear reactors.

Electronic Configuration of Americium

Americium (Am), with 95 electrons, fills its orbitals based on the Aufbau principle. Its complete electron configuration is 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f⁷7s², showing the filling of the 5f subshell before 6d with seven electrons (5f⁷) due to specific energy level arrangements.

Electronic Configuration of Americium via Bohr Model

Image showing Electronic Configuration of Americium via Bohr Model

Electronic Configuration of Americium via Aufbau Principle

Image showing Electronic Configuration of Americium via Aufbau Principle


  • Americium is one of the few elements that is named after a continent, in this case, the Americas.
  • It has no known biological function and can be harmful to living organisms if ingested or inhaled.
  • Americium was first used in commercial applications in the 1950s, primarily in smoke detectors.


  • Americium is primarily used in smoke detectors, where it is used to ionize air particles and create a small electric current that is disrupted when smoke enters the detector.
  • It is also used in some types of nuclear batteries, where the alpha particles emitted by Americium can be used to generate electricity.
  • Americium has potential applications in nuclear weapons and nuclear reactors, but its use is heavily regulated due to its radioactivity.