What is Fermium?

Mary McMahon
Mary McMahon

Fermium is a metallic chemical element classified among the actinide series on the periodic table of elements. It is also what is known as a transuranic element, meaning that it has an atomic number higher than that of uranium. Transuranic elements share a number of interesting traits, but their most distinctive trait is probably their extreme instability. These elements are very reactive and they have very short half lives, and as a result they are rarely, if ever, found in nature. This makes them highly challenging to study, as they are difficult to obtain and when they are available, it is typically only in very small amounts.

On the periodic table of elements, fermium has the atomic number 100, and the element's symbol is Fm.
On the periodic table of elements, fermium has the atomic number 100, and the element's symbol is Fm.

The chemical properties of this element are not really known, although it is presumed to share traits with other actinides. Scientists have succeeded in creating only very small amounts of fermium artificially, so while the existence of the element has been proved, little more is known about it. It is most certainly highly radioactive, and 10 fermium isotopes have been identified by bombarding plutonium with neutrons. On the periodic table of elements, you can find fermium under atomic number 100; the element's symbol is Fm.

This element was first identified in 1952 by Albert Ghiorso and a team of physicists who were studying the residue left behind by explosions of atomic bombs in the South Pacific. These test explosions revealed a great deal about the nature of such devices, along with their byproducts. The discovery of fermium was actually kept secret until 1955, due to the Cold War; government officials were afraid that the Soviets might utilize the element as a potential weapon.

Ghiorso and his team were given the honor of naming their discovery, by convention, and they chose to name it for Enrico Fermi, a prominent Italian physicist who died in 1954. Fermi did a great deal of work on the reactions which were used to synthesize fermium in the laboratory, making this naming particularly apt. The element also briefly went by centurium, in a reference to its atomic number, but this name was later abandoned.

Like other radioactive elements, there is a potential health risk to fermium. However, since the element is so rare, this risk is not a concern for most people. The handful of people who work with elements like fermium, along with their isotopes, have special training in dealing with radioactive material to ensure that their work is safe.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


@David09 - When I read articles about something like the fermium element and discover that for all intents and purposes, there is no practical use for it, it makes me think that a lot of this research is purely academic.

I guess that’s okay, and I suppose there will always be those class of scientists who are interested in purely theoretical research, but I would prefer if scientists would spend more time developing practical applications (and elements or whatever) than those that can only exist inside of a lab.


The fear that the United States had about fermium during the Cold War was unjustified in my opinion.

The Soviets already had the bomb, and it’s doubtful that the fermium could have really been a potential weapon had it been discovered. I would think that if you were going to weaponize anything, you would choose to do it with a material that you could easily produce.

At least from my cursory reading of the article, it doesn’t appear that it was very easy to create the fermium, and its half life was short.

Nowadays of course we have other potential threats in the field of weaponry, like chemical and biological agents. I think that fermium will for the most part remain an academic or textbook phenomenon.


When I looked up fermium I discovered that they found it in coral, which I thought was interesting. Apparently they discovered the 99th element in paper which was used for that purpose around the nuclear test sites, and someone speculated that they might find an even heavier element as well.

So they shipped a bunch of contaminated coral to the laboratory and that's where they managed to find fermium, which is the next number along in the periodic table.

Now I think they only "discover" new elements when they deliberately set out to make them, but it must have been quite exciting to be finding new ones back then.


@anon169520 - Unfortunately, I don't think there are two uses for fermium unless you count different kinds of research. It is quite difficult to make elements that don't exist in nature, and they don't last very long once you do (I believe there is an isotope of fermium which will last for several months, but that's about it).

They have to make fermium, for example, using a nuclear reactor. I think it would be difficult to find a use for it that would justify that, when it doesn't last very long after being made.

For the most part, people would be using it simply to study its nature and thus learn more about the nature of matter and subatomic particles and possibly radiation as well.


I need two uses for fermium, but all I get is "radioactive research". So frustrating!

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