What determines how radioactive an atom is

if the atom is unstable or stable if the forces among the particles that makes up the nucleus are balanced or unbalanced.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."