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).
Four things can happen when radiation enters a cell: 1. The radiation may pass through without any damage occurring; 2. The radiation may damage the cell, but the cell repairs the damage; 3. The radiation may damage the cellâ¦the damage is not repairedâ¦and the cell. replicates itself in the damaged form; 4. The cell dies.