Isotopes through the looking glass

Nuclear distributions affect many aspects of atomic spectra. As an example, recent experimental results for the hyperfine anomaly in Fr isotopes are c onsidered. These depend on nuclear charge and magnetization distributions. The variations in charge radii for these isotopes were studied earlier by m easuring optical isotope shifts. The hyperfine anomalies for the odd-odd is otopes involve the neutron distributions, of interest for studies of parity nonconserving effects along a chain of isotopes.