For now, they're known by working names, like ununseptium and ununtrium — two of the four new chemical elements whose discovery has been officially verified. The elements with atomic numbers 113, 115, 117 and 118 will get permanent names soon, according to the International Union of Pure and Applied Chemistry.
With the discoveries now confirmed, "The 7th period of the periodic table of elements is complete," according to the IUPAC. The additions come nearly five years after elements 114 (flerovium, or Fl) and element 116 (livermorium or Lv) were added to the table.
The elements were discovered in recent years by researchers in Japan, Russia and the United States. Element 113 was discovered by a group at the Riken Institute, which calls it "the first element on the periodic table found in Asia."
Three other elements were discovered by a collaborative effort among the Joint Institute for Nuclear Research in Dubna, Russia, the Lawrence Livermore National Laboratory in California. That collaboration has now discovered six new elements, including two that also involved the Oak Ridge National Laboratory in Tennessee.
Classified as "superheavy" — the designation given to elements with more than 104 protons — the new elements were created by using particle accelerators to shoot beams of nuclei at other, heavier, target nuclei.