These four superheavy elements -- they break down into lighter elements quickly -- were synthesized between 2002 and 2010 by Japanese, Russian and American teams. The scientists sent in their name proposals in June but had to go through a five-month waiting period.

Wondering how the teams came up with those names? The Japanese researchers who created element 113 based Nihonium from the word "Nihon," which means Japan in the country's language. Element 115's Russian creators named it Moscovium after Moscow, while their countrymen who made element 118 (with the help of American scientists) named theirs Oganesson after Yuri Oganessian. He's a Russian nuclear physicist who helped discover the heaviest elements in the periodic table. Finally, the Oak Ridge National Laboratory scientists, who also helped create element 115, named element 117 Tennessine after their home state of Tennessee.