The existence of element Flerovium (previously known as Ununquadium) (element 114) was confirmed in January 2009 at Berkeley, US. It appears to behave as the first superheavy element that shows noble-gas-like properties - possibly due to relativistic effects caused by extreme velocities in its electron shells.

It is extremely radioactive, and has a half-life of around 2 seconds.

• Its appearance is unknown. • Its category is unknown (but, as noted above, it's suspected to resemble the noble gases, i.e. neon, argon, xenon etc.). • Its phase properties (gas/liquid/solid) are unknown.

All info via Wikipedia

Note: Flerovium is just one example of a group of 'synthetic' (i.e man-made rather than naturally occurring) elements that have been created in laboratory conditions. Many have only been made in quantities of just a few atoms - and most tend to decay very rapidly. For those reasons, the physical properties of such elements are generally unknown.

Examples include Moscovium, Bohrium, Oganesson, Darmstadtium, Meitnerium, Roentgenium, Tennessine, Seaborgium, Livermorium etc.

There are likely to be many more, as yet unmade, as predicted by the 'Island(s) of Stability' theory.