User:Rgbc2000/Unsepttrium

Unsepttrium (oon-sept-trium) is the temporary IUPAC name for the hypothesized element having the atomic number 173 and the temporary (until it is made and confirmed) element symbol Ust. Unsepttrium is hypothesized to be the last element ever to be made due to the intense repulsive force of 173 positively charged protons in the nucleus.