What happens to a compound when one of its atoms changes via spontaneous nuclear reaction to an atom with very different bonding? For example, beryllium-7 turns into lithium-7 with a half-life of 53 days. After 53 days half the divalent Beryllium in a crystal of BeF2 would be monovalent Lithium ions. Half of the flourine atome formerly bonded to the former Beryllium atoms would be "floating free", not something Fluorine is wont to do. What would actually happen? Would there be a fluorine ion trapped in the crystal? A flourine atom? Some kind of radical?
Plainly energies available from the nuclear reaction are orders of magnitude larger than anything that would ever be available in chemical bond energies, so even crazy unstable species have plenty of energy to form.