Element:	Roentgenium
Symbol:	Rg
Atomic number:	111
Atomic weight:	[272]
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Valence

Origin of name: after Wilhelm Roentgen, discoverer of x-rays

On December 20, 1994, scientists at GSI Darmstadt, Germany, announced they had detected three atoms of a new element with 111 protons and 161 neutrons. This element was made by bombarding ⁸³Bi with ²⁸Ni. Signals of Element 111 appeared for less than 0.002 sec, then decayed into lighter elements including Element ²⁶⁸109 and Element ²⁶⁴107. These isotopes had not previously been observed. In 2004 IUPAC officially approved the name roentgenium for Element 111.

Roentgenium is expected to have properties similar to gold.