Only a few atoms of the element have ever been produced, and scientific research on this element is hindered by the extreme short half lives of its isotopic forms. The most stable isotope of roentgenium, number 280, has a half life of only 3.6 seconds. Eleven other isotopic forms of roentgenium are known, and they have half lives that are measured in milliseconds.
Roentgenium was not synthesized until 1994. At this time, three atoms were created using the elements bismuth and nickel. During the procedure, bismuth and nickel underwent a fusion reaction in a linear accelerator; the bismuth isotope, number 209, served as the target which was bombarded by nickel isotopes, number 64, to produce the isotope of roentgenium, number 272, and one neutron. From its brief existence, it was predicted to have some chemical properties similar to gold, and therefore it is sometimes called eka-gold.
