Natural transmutation is the spontaneous disintegration of a heavy nuclide into lighter ones or fusion of lighter nuclides into heavier ones. These processes occurs naturally without anything inducing them. Nuclear fission of light elements in the core of stars is an example of natural transmutation.
Typically, all nuclei with atomic number greater than 83 are naturally radioactive.
²³⁸₉₂U → ²³⁴₉₂Th + ⁴₂He
In artificial transmutation, nuclear reactions are initiated through the collision of a nuclide with a high speed particle. Here, unstable nuclei are produced artificially in nuclear reactions. Such unstable nuclei also produce radiations.
