0.625 moles of ge X 6.02x10^23 atoms/ 1 mol of ge equal to 3.76x10^23 atoms of ge, just times with Avogadro.
Beta radiation / decay would likely occur when the ratio of protons to neutrons is below the band of stability.
Main group elements
transition metals
lanthanides
actindes.
The right answer is 2.
The number of protons contained in a nucleus (called an atomic number) is characteristic of a chemical element. For a given atomic number, the number of neutrons defines different "types" of this element: isotopes. The variation of the number of protons of the nucleus of an atom, during a nuclear reaction for example, causes a change of the element studied.
