For ten points, name this precious metal whose purity is measured on a scale up to 24 karats.
During an experiment named for this material, Hans Geiger counted flashes of light on a zinc sulfide screen, generated after an alpha particle was shot at a foil of this metal; that experiment was overseen by Ernest (*) Rutherford. This highly malleable metal dissolves in aqua regia and is used in electrical connectors to prevent corrosion. For ten points, name this precious metal whose purity is measured on a scale up to 24 karats.
During an experiment named for this material, Hans Geiger counted flashes of light on a zinc sulfide screen, generated after an alpha particle was shot at a foil of this metal; that experiment was overseen by Ernest (*) Rutherford.
gold (accept Rutherford gold foil experiment)