Element numbers 113, 115, 117 and 118 will no longer be known by their placeholder names, and instead have all-new monikers decided upon by their discoverers. Here are the new names:

Element 113: nihonium (Nh)

Element 115: moscovium (Mc)

Element 117: tennessine (Ts)

Element 118: oganesson (Og)

The IUPAC announced in January that the four elements would land on the periodic table, though the elements remained nameless. Scientists first synthesized the new elements between 2002 and 2010, but it wasn’t until last December that the International Union of Pure and Applied Chemistry (IUPAC) officially recognized the discoveries. Scientists with Japan's RIKEN Nishina Center for Accelerator-Based Science proposed the element name nihonium, which is one way to say "Japan" in Japanese and means "the land of the rising sun," according to the IUPAC. “IUPAC has now initiated the process of formalising names and symbols for these elements temporarily named as ununtrium, (Uut or element 113), ununpentium (Uup, element 115), ununseptium (Uus, element 117), and ununoctium (Uuo, element 118).”

New elements can be named after a mythological concept, a mineral, a place or country, a property or a scientist. The name oganesson, for element 118, honors Yuri Oganessian "for his pioneering contributions to transactinide elements research," IUPAC officials said, referring to elements with atomic numbers 104 through 120.
The International Union of Pure and Applied Chemistry announces official names for recently-discovered superheavy elements Nihonium (113), Moscovium (115), Tennessine (117), and Oganesson (118).