Hydrogen bomb , Peaceful uses of the radioactive isotopes and Harmful effects of Nuclear radiations
Nuclear fusion reaction
It is the source of the destructive energy of the Hydrogen bomb , It is the fusion of two light nuclei to form a heavier nucleus of a mass smaller than the sum of the masses of the fused nuclei , such as Fusion of two deuterons to form He-3 .
During the fusion of the two deuterons together , the mass of the products is less than the mass of reactants and the difference in mass transformed to energy = 24 Me V that is freed with the fusion of these two deuterons .
Although the nuclear fusion occurs inside the sun , but it is difficult to be achieved in laboratories because the nuclear fusion reaction requires a high temperature that reaches to rank 107 K , which can’t be achieved in laboratories .
Nuclear reactions occur through the nucleons of the nucleus , Almost there is a transformation of an element to another on or its isotope , Isotopes of the same element give different products , They are accompanied by releasing a huge amount of energy .
Chemical reactions occur between the electrons of the outermost shells of the atom , There is no transformation for the element to another one , Isotopes of the same element give the same products , They are accompanied by releasing or absorbing a small amount of energy .
Peaceful uses of the radioactive isotopes
The medical field
Destroying carcinogenic cells by : Directing the gamma rays ( γ ) emitted from cobalt- 60 or cesium-137 radioactive isotopes to the center of the tumor , Implanting needles made from radioactive radium-226 isotope in the carcinogenic tumor to destroy it .
The industrial field
Automation of some production lines such as in the pouring of molten steel , In which the source of gamma rays ( γ ) ( cobalt-60 or cesium-137 isotopes ) is placed at one of the sides of pouring machine and a radiations detector which is sensitive to γ – rays is placed on the other side .
When the iron mass reaches certain dimensions , the detector can’t receive the γ – rays and thus the pouring process stops .
The agricultural field
Create mutations in embryos and select the finest of them to produce plants of greater productivity and resistance to diseases by exposing the seeds to different dosages of γ – rays .
Sterilization of the plants and animal products by using γ – rays to preserve them from spoiling and increase their storage time , Sterilize male insects by using γ – rays to limit the spread of agricultural pests .
The scientific researches field
Tracing the cycle of some substances in plants by placing radioactive isotopes in the main substances that plants use , then trace the emissions from these substances to know their cycle in the plant , like inserting water that has radioactive oxygen-18 to the plant and following its track .
Harmful effects of Nuclear radiations
There are two types of radiations which are Ionized radiations and Non – ionized radiations .
They are the radiations that cause changes in the composition of tissues exposed to them , Such as α – radiations , Β – radiations , γ – rays and X – rays .
Ionized radiations Harms
The exposure of the cell to the ionized radiations leads to its damage ( ruining ) as the follows :
- The ionization of water molecules that represent the larger part of any living cell .
- The breaking of the chromosomes .
- Some genetic deformations .
- The continuous exposure to the ionized radiations , Some changes occur to the cell that lead to preventing or delaying the cell division or increasing the rate of its division , which leads to carcinogenic tumors , Occurrence of permanent changes in the cell that is genetically transported to the next generations , The result is the birth of new infants that are different from their parents & Death of the cells .
The ionized radiations are called with that name or the X- rays is one of the ionized radiation because of falling of these radiations on any living bodies causing ionization of the atoms or molecules that the cells are composed from .
Non – ionized radiations
They are the radiations that do not cause change in the composition of tissues that are exposed to them , Such as Radio waves emitted from cellular phones , Microwaves , Infrared rays , Ultraviolet ray , Laser rays and Visible rays .
Non – ionized radiations Harms
The radiations emitted from the cellular towers may cause physiological changes in the nervous system that appear as Headaches , Dizziness and fainting symptoms , Scientists have agreed that the distance between cellular towers and households must be safe ( at least 6 meters ) .
The electric and magnetic fields of the radio waves emitted from the cellular phones are dangerous on the body cells and also cause an increase in their temperature , due to the absorption of these rays by the cells , Some studies have noted that the use of laptops by placing them on the knees affects fertility .