Roentgenium (Rg)
Atomic Number 111
Atomic Mass: 280
Atomic Number: 111
Number of protons: 111
Number of Neutrons: 179
number of electrons: 111
Element Family: Transition Metals
Boiling Point: Unknown
Melting Point: Unknown
Discovered by: Sigurd Hofman on December 8, 1994
Was named in honor of German Physicist Wilhelem Conrad Rontgen
There are 12 known isotopes
It is silvery
It is a solid