The decay of the very neutron-rich nucleus 100 Rb has been studied by γ spectroscopy of online mass-separated samples. Schemes for β decay to 100 Sr and β n decay to 99 Sr are presented. New sets of transitions in 99 Sr and 100 Sr with identical energies are observed. All identical bands so far observed in neutron-rich Sr isotopes obey a simple energy rule valid for even-even, odd-even, and odd-odd bands.