1) Into what isotope does Americion 213 decay when undergoing alpha decay ? 243 4 95 Am 2 He 2 ) What isotope decays into Lanthanium 141 when it undergoes beta decay ? 141 52 La + -1 B 3) Use bX ( where a is the atomic mass, and b is the atomic number) to indicate the symbol of heavy hydrogen when it undergoes gamma ( 1 ) decay . 3 H ? + Ephoton Y 4) What happens to an atom of Nobelium 255 that undergoes a process of electron capture ? 255 Note - ? + neutrino 105 5) In a process of positron emission what does the atom of magnesium 23 become? 23 Mg ? + + 1 12