Atomic radiation is one of the most dangerous.Its consequences are unpredictable for humans. What is meant by the concept of radioactivity? What do the words "large" or "smaller" radioactivity mean? What particles are included in the composition of different types of atomic radiation?
The composition of radioactive radiation may includedifferent particles. However, all three types of radiation belong to one category - they are called ionizing. What does this term mean? The energy of radiation is incredibly high - so much so that when the radiation reaches a certain atom, it knocks out an electron from its orbit. Then the atom, which became the target of radiation, becomes an ion, which is positively charged. That is why atomic radiation is called ionizing, to whatever type it belongs. High power distinguishes ionizing radiation from other types, for example from microwave or infrared radiation.
To understand what can be included in theradioactive radiation, it is necessary to consider in detail the ionization process. It occurs as follows. The atom looks like a small poppy seed (the nucleus of the atom), surrounded by the orbits of its electrons, like a shell of a soap bubble. When radioactive decay occurs, the smallest grain - an alpha or beta particle - is emitted from this nucleus. When the charged particle is emitted, the charge of the nucleus also changes, which means that a new chemical is formed.
Particles that make up the radioactiveradiation behave as follows. A grain flying away from the nucleus rushes with a giant speed ahead. On its way, it can crash into the shell of another atom and in the same way knock out an electron from it. As already mentioned, such an atom will turn into a charged ion. However, in this case the substance remains the same, since the number of protons in the nucleus remains unchanged.
Knowledge of the processes listed allows us to estimatethen how much radioactive decay occurs. This value is measured in becquerels. For example, if one decay takes place in one second, then they say: "Isotope activity is 1 becquerel". Once, instead of this unit, a unit called curie was used. It was equal to 37 billion becquerels. It is necessary to compare the activity of the same amount of substance. The activity of a certain unit of isotope mass is called specific activity. This quantity is inversely proportional to the half-life of one or the other isotope.
Ionizing radiation can not occuronly in the case of radioactive decay. To serve as sources for radioactive radiation can be: the fission reaction (occurs as a result of an explosion or within an atomic reactor), the synthesis of so-called light nuclei (occurring on the surface of the sun, other stars, and also in a hydrogen bomb), as well as various accelerators of charged particles. All these sources of radiation are united by one common feature - the most powerful level of energy.
Differences between the three types of ionizing radiation- alpha, beta and gamma - are in their nature. When these emissions were discovered, no one had a clue what they could represent. Therefore, they were simply called the letters of the Greek alphabet.
As their name implies, the alpha rays wereopen first. They were part of the radioactive radiation in the decay of heavy isotopes, such as uranium or thorium. Their nature was determined after a lapse of time. Scientists have found out that alpha radiation is quite heavy. In the air, it can not overcome even a few centimeters. It turned out that the nuclei of helium atoms can be included in the composition of the radioactive radiation. This is true for alpha radiation.
Its main source is radioactiveisotopes. In other words, it represents positively charged "sets" of two protons and the same number of neutrons. In this case, it is said that the composition of radioactive radiation includes aparticles, or alpha particles.Two protons and two neutrons form the core of helium, which is characteristic of alpha radiation. For the first time in humanity such a reaction was able to get E. Rutherford, who was engaged in the transformation of nitrogen nuclei into oxygen nuclei.
Then it turned out that the radioactiveradiation can include not only helium nuclei, but also ordinary electrons. This is true for beta radiation - it consists of electrons. But their speed is much greater than the speed of alpha radiation. This type of radiation also has a smaller charge than alpha radiation. From the parent atom, the beta particles "inherit" a different charge and a different speed.
It can reach from 100 thousand.km / sec up to the speed of light. But in the open air, beta radiation can spread a few meters. The penetrating ability is very small. Beta rays can not overcome paper, cloth, thin metal sheet. They only penetrate this matter. However, irradiation without protection can lead to a burn of the skin or eye, as it does with ultraviolet rays.
Negatively charged beta particles arethe name of the electrons, and positively charged are called positrons. A large number of beta radiation is very dangerous for humans and can lead to radiation sickness. Much more dangerous can be ingestion of radionuclides.
Next, gamma radiation was discovered.In this case, it turned out that the composition of radioactive radiation can include photons with a certain wavelength. Gamma radiation is similar to ultraviolet, infrared rays of the radio wave. In other words, it represents electromagnetic radiation, but the energy of the photons entering into it is very high.
This type of radiation has an extremely highthe ability to penetrate any obstacles. The denser the material in the path of this ionizing radiation, the better it can detain dangerous gamma rays. For this role, lead or concrete is often chosen. In the open air, gamma radiation can easily overcome hundreds and thousands of kilometers. If it affects a person, it leads to damage to the skin and internal organs. By its properties, gamma radiation can be compared with the X-ray. But they differ in their origin. After all, X-rays are obtained only under artificial conditions.
Many of those who have already studied what rays are includedin the composition of radioactive radiation, are convinced of the dangers of gamma rays. After all, they can easily overcome many kilometers, destroying people's lives and leading to a terrible radiation sickness. In order to protect themselves from gamma rays, nuclear reactors are surrounded by huge concrete walls. Small pieces of isotopes are always placed in containers made of lead. However, the main danger for a person is the radiation dose.
Dose is the amount that is usuallyis calculated taking into account the body weight of a person. For example, for a single patient, a dose of 2 mg will be appropriate. For another, the same dose may have an adverse effect. The dose of radioactive radiation is also evaluated. Its danger is determined by the absorbed dose. To determine it, first measure the amount of radiation that was absorbed by the body. And then this amount is compared with the body weight.
Different types of radiation can have differentharm to living organisms. Therefore, it is impossible to confuse the penetrating power of various types of radioactive radiation and their damaging effect. For example, when a person can not protect himself from radiation, alpha radiation is much more dangerous than gamma rays. After all, its composition includes heavy nuclei of hydrogen. And a type such as alpha radiation shows its danger only when it enters the body. Then internal irradiation takes place.
So, in the composition of radioactive radiation canthere are three types of particles: they are helium nuclei, ordinary electrons, and also photons with a certain wavelength. The danger of this or that type of radiation is determined by its dose. The origin of these rays does not matter. For a living organism, there is absolutely no difference, from where the radiation has accumulated: whether it's an X-ray machine, the Sun, an atomic station, a radon spa or an explosion. Most importantly, how many dangerous particles were absorbed.
Along with the natural radiation backgroundhuman civilization is forced to exist among many artificially made sources of dangerous ionizing radiation. Most often it is the result of terrible accidents. For example, the disaster at the nuclear power plant "Fukushima-1" in September 2013 led to the leakage of radioactive water. As a result, the content of isotopes of strontium and cesium in the environment has grown many-fold.
