Nepedia
Back to Discover
Fluent Reader
⚛️

Americium

physical science Maturity 11-13 Next article →

Americium is a special kind of metal. It is a synthetic element, which means people make it in a lab. It has the symbol Am and the atomic number 95. This metal is also radioactive. This means it gives off energy over time. It looks like a soft, silvery metal.

Closest packing ABAC
Closest packing ABAC

It sits in the actinide series on the periodic table. Because of its place, it was named after the Americas.

Most americium is made in nuclear reactors. Scientists do this by hitting uranium or plutonium with neutrons. A neutron is a tiny particle. When plutonium-239 captures two neutrons, it becomes plutonium-241. This plutonium then undergoes beta decay. This is a process where one part of the atom changes. This change turns the plutonium into americium-241.

One tonne of spent nuclear fuel contains about 100 grams of americium.

Researchers first made americium in 1944. A group led by Glenn T. Seaborg worked on this. They worked at the University of California, Berkeley. They also used the Metallurgical Laboratory in Chicago. They were part of the Manhattan Project. The team included Leon O. Morgan, Ralph A. James, and Albert Ghiorso. They used a huge 60-inch cyclotron to help their work.

Berkeley 60-inch cyclotron
Berkeley 60-inch cyclotron

The discovery was kept secret at first. It was only shared with the public in November 1945.

Americium is used in many helpful ways today. You might find it inside a smoke detector. These use an ionization chamber to work. It is also used in industrial gauges and neutron sources. Some scientists have even thought of using a special version called 242mAm for space. It could act as fuel for ships with nuclear propulsion.

Ivy Mike - mushroom cloud
Ivy Mike - mushroom cloud

However, this is hard to do right now. This specific type is very expensive and hard to find.

Even though it is man-made, it can appear in other places. It was found in the fallout from the Ivy Mike nuclear test. It can also be found near sites of nuclear incidents. For example, it was found at the Chernobyl site. It was also seen in the Trinitite glass near New Mexico. In most soil, the amount of americium is very tiny. It usually sticks to the particles in the dirt. This makes it stay in one place rather than moving in water.

379 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (4)
File:Berkeley 60-inch cyclotron.jpg
Berkeley 60-inch cyclotron.jpg
File:Ivy Mike - mushroom cloud.jpg
Ivy Mike - mushroom cloud.jpg
File:Elutionskurven Tb Gd Eu und Bk Cm Am.png
Elutionskurven Tb Gd Eu und Bk Cm Am.png
File:Closest packing ABAC.png
Closest packing ABAC.png
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.