Synthetic element

A chemical element produced artificially, typically through nuclear reactions, rather than occurring naturally in appreciable amounts. Many synthetic elements are radioactive and decay rapidly.

Nuclear transmutation: The conversion of one atomic nucleus into another through radioactive decay or a nuclear reaction. Synthetic elements are made by changing a target nucleus into one with a different proton count.
Atomic number: The number of protons in an atomic nucleus, which defines the chemical element. Producing a new element requires creating a nucleus with a previously distinct proton count.
Technetium: Element 43, a radioactive transition metal with no stable isotopes. It became the first element discovered through deliberate artificial production.
Technetium discovery: The 1937 identification of element 43 in material irradiated in a cyclotron. This experiment established the first confirmed artificially produced element.
Island of stability: A predicted region of superheavy nuclei with longer half-lives than neighboring isotopes. It could make some synthetic elements easier to study if the predicted nuclei exist.
Particle accelerator: A device that uses electromagnetic fields to accelerate charged particles to high energies. Accelerators propel projectiles into target atoms to produce many synthetic nuclei.
Isotope: One of two or more atoms of the same element with different numbers of neutrons. Synthetic elements are usually first detected as particular isotopes, not as bulk substances.
Promethium: Element 61, a radioactive lanthanide with no stable isotopes. Its discovery in fission products established another element absent from appreciable natural deposits.
Edwin McMillan: An American physicist who co-discovered neptunium and helped establish the transuranium elements. His neutron-irradiation experiments opened the route to elements beyond uranium.
Nuclear shell model: A model describing nuclear structure through energy levels occupied by protons and neutrons. Its predicted shell closures guide searches for unusually stable superheavy isotopes.

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