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Ununtrium is located on the periodic chart in group 13 (IIIA) just below thallium andindium. It is expected to have chemical and physical properties similar to these two homologues.Since only one or two unstable atoms of the isotopes of ununtrium have been synthesized,its melting point, boiling point, and density are not known.

There are five isotopes of ununtrium, ranging from Uut-283 to Uut-287. Its moststable isotope is Uut-284, with a half-life of 0.48 seconds, which is used as its proposedstandard mass number.

The IUPAC assigned the temporary name “ununtrium,” which literally means 113.

In 2003 the Nuclear Research Laboratory in Dubna, Russia, and the Lawrence LivermoreNational Laboratory in California, collaborated in conducting a 27-day experiment that led tothe discovery of ununtrium. They bombarded atoms of americium-243 with ions of calcium-48. This produced, among other particles, four atoms of ununpentium (element 115), whichin less than 1/10 of a second decayed by alpha emission into atoms of ununtrium (element113). Since no formal name has yet been proposed for element 113, IUPAC’s temporary namingsystem was used to name element 113 “ununtrium” (113).Following is one example of the nuclear reaction wherein an isotope of element 115 (ununpentium)decays within a few milliseconds into an isotope of element 113 (ununtrium-283),which in turn decays into element 111 (unununium):₁₁₅Uup-283 → ₁₁₃Uut-283 + ₂He-4 → ₁₁₁Uuu-279 + ₂He-4.(Note: This first reaction occurs in just 46.6 milliseconds, and the second reaction occursin 147 milliseconds. Similar nuclear decay reactions of element 115 result in several otherisotopes of ₁₁₁Uut-284 with various fission decay rates into element 111.)

Since only a few atoms of ununtrium have been produced, there are currently no uses ofelement 113 outside of basic nuclear research.

No hazards exist for the general public because only a few radioactive unstable atoms ofununtrium have been produced in nuclear laboratories.