A major research institution has recently announced the discovery of the heaviest NEW chemical element yet known to science.  The new element has been tentatively named Governmentium.

Governmentium has 1 neutron, 12 assistant neutrons, 75 deputy neutrons, and 224 assistant deputy neutrons, giving it an atomic mass of 312.  These 312 particles are held together by forces called morons, which are surrounded by vast quantities of lepton-like particles called peons.  Since Governmentium does not have electrons, it is therefore inert.  However, it normally can be detected as it impedes every reaction with which it comes into contact.  Governmentium has a normal half-life of 4 years; it does not decay, but instead undergoes a reorganization in which a portion of the assistant neutrons and deputy neutrons exchange places.  In fact, Governmentium's mass will actually increase over time, since any reorganization will cause some morons to become neutrons, forming isodopes.  This characteristic of moron-promotion leads some scientists to speculate that Governmentium is formed whenever morons reach a certain quantity in concentration.  This hypothetical quantity is referred to as "critical morass".

...thanks to my colleague Martin Stuart :)

P.S. In sailing there is always a desire to have the densest possible material for keel ballast.  For years lead was used, but more recently in high end yachts the denser and far more expensive material depleted uranium is used.  (This also has the side benefit of yielding lots of radioactivity jokes for the crew.)  Lead has an atomic mass of 207, Uranium has 238.  So Governmentium at 312 would be far denser.  Of course anything ballasted with Governmentium might have too much inertia to move at all...