The synthesis of superheavy elements is a challenge for experimental physics that raises fundamental questions about nuclear structure and stability. [1] Considerable progress has already been made with the synthesis of elements with atomic numbers up to Z = 118, [2][3][4][5] and with the development of real atom-at-a-time chemistry for elements with atomic numbers up to Z = 108 [6,7] to explore their often anomalous behavior. However, the detection of these elements relies on a good understanding of their chemical and physical properties.
For the transactinide series, which begins with rutherfordium (Z = 104), experiments have been performed to correctly place the elements in the Periodic Table and to address the question of whether the Periodic Table is even useful for their categorization. Owing to the very small half-lives of these elements (t 1/2 = 78 ( 261104 Rf) to 14 s ( 269 108 Hs)), such experiments involve nonstandard procedures and often rely on theoretical predictions for unambiguous interpretation. [8,9] The latest superheavy element for which atom-at-a-time chemistry is planned is element 112, [10][11][12] eka-mercury (t 1/2 4 s for 283 112 [13] ). The chemistry of element 112 is controversial: earlier predictions ranged from mercury-like properties [16,17] to noble-gas-like behavior [8,18,19] resulting from the strong relativistic contraction of the 7s shell. Hence, model studies based on the assumed similarity of element 112 to either the noble gas radon or to the transition metal mercury have been conducted. [10-12, 14, 15] Predicted data for the elements 112 and 114 were used to correlate their sublimation and adsorption behavior on metal surfaces. [20,21] Such predictions are extremely valuable for the design of sophisticated experimental setups for the chemical investigation of the transactinide elements on a single-atom scale.