Ununtrium
Atomic Symbol Uut
Atomic Number 113
Atomic Weight unknown
presumably a solid at 298 K
Color unknown, but probably metallic and silvery white or grey in appearance

Ununtrium is a synthetic element that is not present in the environment. Isolation of an any quantity of ununtrium has never been achieved, and thus ununtrium has no known uses. The reactivity of ununtrium is unknown, but is assumed to be similar to thallium and indium.

In July and August of 2003, ununpentium and ununtrium were successfully produced by a team made up of scientists from Lawrence Livermore National Laboratory in California and the Joint Institute for Nuclear Research in Dubna, Russia.

In Dubna, scientists fired a rare isotope of calcium at americium. Four times during a month of continuous bombardment, a calcium nucleus fused with an americium nucleus and created the new element, number 115.

The atoms of element 115 decayed into ununtrium, element 113, in a fraction of a second. The atoms of 113 lasted for as long as 1.2 seconds before decaying to known elements.

No name has yet been suggested for element 113, which is therefore called ununtrium, from the Latin roots un for one and tri for three, under a convention for neutral temporary names proposed by the International Union of Pure and Applied Chemistry (IUPAC) in 1980.

             thallium
                 ^
ununbium <-- ununtrium --> ununquadium