what is element of periodic table 111's (Roentgenium) electons and neutrons?
its atomic mass is 272.
i know the protons is 111.
if so can you tell me if it is stble or not.
- 1 decade agoFavorite Answer
Protons = 111
Electrons = 111
Mass Number = (Number of Protons) + (Number of Neutrons)
Neutrons = 161
Element 111, roentgenium, was discovered on 8th December 1994 at the GSI in Darmstadt, Germany. Further information on element 111 is here (outside WebElements). The information following is an abstract of this source. The interested reader should consult the on-line version of The Wonderful World of Atoms and Nuclei (outside WebElements) for a fascinating insight into research on "super-heavy" atoms. Chemically, roentgenium should be in the same group as the elements copper, silver, and gold (Group 11).
Here is a brief summary of the isolation of roentgenium.
Only a few atoms of element 111, roentgenium, have ever been made through a nuclear reaction involving fusion of an isotope of bismuth, 209Bi, with one of nickel, 64Ni.
209Bi + 64Ni → 272Rg + 1n
Isolation of an observable quantity has never been achieved, and may well never be.