The IUPAC name "Unununnium" is derived from a systematic element naming method based on the atomic number of elements, primarily used for elements that have not yet been discovered or were not yet officially named at the time. The name "Unununnium" is composed of Latin and Greek numerical roots and can be broken down into "Un-un-un-nium" where "un" represents one and "nnium" is the suffix used for elements. The full name "Unununnium" hence corresponds to the temporary elemental name for an element with the atomic number 111 (one-one-one).

The elements in the periodic table are arranged by their atomic number and grouped by their electron configurations, particularly the valence electrons which determine their chemical properties. Each column of the periodic table is known as a group. The atomic number 111 element, which was named "Unununnium" before its official name "Roentgenium (Rg)" was adopted, is in the same group as copper (Cu), silver (Ag), and gold (Au). This group is group 11 of the periodic table. Therefore: