There are 2 types of nuclear reactions in science known as nuclear fission and nuclear fusion. The disintegration and combination of elemental nucleus is classified under fission & fusion. Both of them are energy reactions but their applications are not the same. While fission is the splitting of heavy nucleus/ atom into smaller/lighter nuclei or atom;fusion on the other hand is the process where two heavy nuclei combine together to form one single nucleus.
| Nuclear Fission | Nuclear Fusion |
When the nucleus of the atom splits into smaller particles though a nuclear reaction. | It is reaction through which two or more light nuclei collide with each other to form a heavier nucleus. |
| Large amounts of energy is released through the splitting of atom. | The energy released here is much more than that in fission |
| These reactions do not occur naturally. | They occur naturally in stars and sun, also other natural processes. |
| Little amount of energy is needed to split the atom into two. | Large amount of energy is needed to fuse two or more atoms together. |
| Example: Atomic bomb | Example: Hydrogen bomb. |
