The elements 113, 115, 117, and 118 have now officially been added to the periodic table. As of December 30th, 2015, Russian and American research has collected enough evidence on the latter three elements to add them permanently to the seventh row of the periodic table, and the IUPAC (the International Union of Pure and Applied Chemistry) has gotten evidence on element 113.

Element 113, named Ununtrium, is entirely synthetic, and has not been found in nature. It is believed to be a post-transition metal, despite being a ‘p-block’ element. In 2004, a single atom of the isotope was made in 2004 after scientists hit bismuth with zinc nuclei. Element 113 is very heavy and pretty unstable, though the scientists found that the heavier the atom, the more stable the element was.

Element 115, with the lovely name of ‘Ununpentium,’ is radioactive. Its half-lifespan is only 220 miliseconds, and it was first seen in 2003 by scientists in Russia. It is suspected to contain the elements of copermicium and flerovium. It belongs to the ‘pnictogens’ group of elements on the table. It’s atomic mass is 288 u.

Element 117, Ununseptium, is incredibly heavy: it is actually the second-heaviest element known. Its melting point is predicted to come at about 570 degrees Fahrenheit. Scientists began to look for this element in earnest in 2004, and believe that this element will be a metalloid with a trigonal configuration. Though the element was seen in 2004, its daughter isotopes were not discovered until nearly three years later.

Ununoctium, Element 118, is highly radioactive and very unstable. Only a few atoms have been created since its initial discovery in 2005, even though scientist have been attempting to create this super heavy atom since the late 1980s. There were several false reports about the discovery of the atom made up unitl 2005, when the atom was actually synthesized. Scientists believe that Ununoctium will be a noble gas.

With the seventh row of the periodic table filled up, there are questions about whether or not there are any more elements. Some scientists believe that some elements that have only been created in the lab, like element 113 or, more commonly seen, 94 -- plutonium -- may be in nature and just have to be discovered there. This may be the next goal of chemists, in addition to seeing if the elements can go beyond 118. There are already predictions for elements 119, 120, and 121.