Illustration: Carin Cain, based on data in [1, 5] and calculations in [2]

Figure 1: A chart of the nuclides, zoomed in on the region of the superheavy nuclei and showing the two isotopes of the new element $117$ and their decay chains (white lines) [1, 5]. The chart shows both expected (calculated) regions of stability [2], as indicated by a higher fission barrier $Bf$ (darker purple) and the elements that have been created in the laboratory to date (colored squares). All of the nuclei lie near the valley of stability above the grey line; nuclei near the grey line are stable against $β$ decay. Compound nuclei, created by bombarding heavy elements with lighter ones, are in blue and marked with $*$. The nuclei in the chart decay by $α$ emission (yellow), spontaneous fission (green), and $β+$ emission (pink).