elishane9783 elishane9783 27-02-2024 Chemistry contestada Rubidium has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 72.2% and the abundance of 87Rb is 27.8%, what is the average atomic mass of rubidium? a) 85.0 b) 86.5 c) 87.0 d) 87.5