Category: (post transition metal)
Density at 25°C: solid: n/a
This is the second to last element in the current structure of the periodic table. Given it's location it is expected to have some similarities to halogens. It is mostly just referred to as 117 in research circles. It has a maximum half life of around 78 milliseconds, but it so far very hard to measure with high accuracy.
update: now officially known as Tennessine (Ts) after the Region in the US Tennessee.