Untriunium
hypothetical chemical element with the atomic number 131
Untriunium, also known as element 131 or eka-Einsteinium, is the possible chemical element in the periodic table with the placeholder symbol of Utu and atomic number 131. Untriunium and Utu are the temporary systematic IUPAC name and symbol, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to follow Untrinilium as the tenth element of the Superactinides and the twelfth element of the 8th Period. Similarly to Untrinilium, it is expected to fall within the range of the island of stability.