Which equation represents a spontaneous nuclear decay?

Spontaneous nuclear decay is from a radioactive isotope, which either releases alpha particles (2neutrons and 2 protons) or beta particles (a high speed electron). so the general equation would be:

radioactive isotope-alpha particle+new radioactive isotope with 2 less protons and 2 less neutrons

or

radioactive isotope-beta particle + new radioactive isotope with 1 more proton and 1 less neutron