Nuclear transmutation is the converting of atoms from one particular element into atoms of another particular element. This can occur through two different processes, fission and fusion. Fission is the breaking down of an atom into smaller elements are particles. This involves a decrease in the number of protons. One example is the breakdown of uranium into lead. Fusion is the fusing together of smaller nuclei into a larger element. An example is the fusing together of two hydrogen atoms to form a helium atom in the sun. This involves an increase in the number of protons. So transmutation can involve either an increase or decrease in the number of protons depending on the particular process used. Neutrons, however, are less predictable. Transmutation can involve the loss, gain, or no change in the number of neutrons depending on the specific reaction.