Symbol: Uut

Category(post transition metal)

Density at 25°C: solid:  n/a

Now this unusually named synthetic element is the current element with no 'official' name. What does Un un trium mean? Well according to IUPAC naming conventions for unnamed or undiscovered elements:  'Un' = 1 , there are two of them, hence the Unun and 'tri' = 3 so it just comes to 113. 

With some clever experiments however, scientists managed to make a few atoms of this briefly and even did a basic chemical test that showed it behaved like an element in group 5 of the periodic table. 286Uut manages a half-life of 20 seconds.

update:  it is now officially known as Nihonium (symbol Nh)  

In March 2016, Kosuke Morita, the leader of the RIKEN team, proposed the name "nihonium" to IUPAC, after its place of discovery and referencing Japanese chemist Masataka Ogawa's 1908 discovery of rhenium, which he named “nipponium"

source adapted from Nihonium. (2016, November 30). In Wikipedia, The Free Encyclopedia. Retrieved 13:27, November 30, 2016, from https://en.wikipedia.org/w/index.php?title=Nihonium&oldid=752288582