The menstrual cycle is from Day 1 of bleeding to Day 1 of the next time of bleeding. Although the average cycle is 28 days, it is normal to have a cycle that is shorter or longer. Girls usually start having menstrual periods between the ages of 11 and 14.
In nuclear physics, nuclear fusion is a nuclear reaction in which two or more atomic nuclei come very close and then collide at a very high speed and join to form a new nucleus. During this process, matter is not conserved because some of the matter of the fusing nuclei is converted to photons (energy).
Fission vs Fusion. Fission and fusion are two different nuclear reactions. Nuclei of atoms have strong binding energies. This energy can be released in two different ways known as fission and fusion reactions. These nuclear reactions release huge amounts of energy. Fusion is said to have taken place when two light nuclei combine together, releasing energy in the process.