Elements - Ernest Rutherford (1871-1937; right) and Hans Geiger (1882-1945) in their laboratory at Manchester University, Manchester, United Kingdom in about 1908. They are seen with the instrumentation they used to detect and count alpha particles from a radio active source. The experiment led to Rutherford identifying alphas particles as helium ions, later shown to be helium nuclei. (Photo: Science Photo Library)
