Radioactivity is a dangerous blessing

Just a little over a century ago, the atom was considered the smallest of particles existing in nature, unchanged and indivisible. But the scientific thought did not stand still, the restless human mind strove to reveal more and more the veil of secrecy over the properties of the elements. And so, at the end of the nineteenth century, the French physicist A. Becquerel, by conducting an investigation of x-rays, accidentally became interested in the radiation emitted by uranium salts. So in 1896, radioactivity was discovered - this is the most obvious proof of the divisibility of the atom.

The scientific community was very interested in the discovery, and a galaxy of talented physicists devoted themselves to its study. As it later turned out, often bringing to the altar of science your health. Thanks to them, we now know that radioactivity is a phenomenon of spontaneous spontaneous emission of different particles by nuclei of a number of elements, in which the nuclei eventually change over to another state and their parameters change.

Atoms of radioactive substances emit particles and electromagnetic rays. Among them are the following:

- alpha particles (α) are a stream of fully ionized helium atoms moving at a speed of 20,000 km / s and having the ability to penetrate into the air at a distance of up to 10 cm. To stop these particles from penetrating the human body, clothing, paper, leather . But having penetrated into the body, they will cause significant harm;

- beta particles (β) are fast electrons (or positrons) whose flux has velocities close to the speed of light. Their penetrating ability in the air is much higher - up to 5 - 20 m. And they can be prevented by an aluminum sheet several millimeters thick;

- gamma rays (γ) - electromagnetic radiation emanating from nuclear interactions and transformations of particles with a very small wavelength. The penetrating power of this type of radiation is so high that it can only be stopped by a thick sheet of lead or a layer of concrete.

With a number of spontaneous nuclear reactions, neutrons are emitted - neutrons whose penetrating power is higher, which in γ-rays - they pass through lead up to several meters thick.

It is known that radioactivity is a property that can be inherent in elements from nature, and can be achieved by laboratory methods. Artificial radioactivity was discovered already in the 30s of the XX century.

There are a lot of sources of natural radiation. This is the very planet Earth, and space, and nuclear power plants with their waste, and chemical elements in soils, and building materials, and a number of household items. But people try not to think about this.

There are several instruments that measure radioactivity, units of measurement are also different. The basic unit is becquerel (Bq), equal to one decay per second. Used and extrasystem units: X-ray, Curie. The absorbed dose is measured in units of rad or gray. The effect on biological organisms is evaluated in a rem or sievert.

Natural radioactive materials emit particles, irradiating us throughout life. One of the sources of irradiation is always artificial buildings - residential and industrial. Even a number of natural materials have a slightly increased radiation background. For example, the natural radioactivity of granite makes the buildings of it twice as radioactive (400 mb / yr) than those built from red bricks, four times - than concrete ones. The less charged particles emit a tree - buildings from it are 13 times less radioactive than granite.

The benefit that radioactivity brings to humanity is an undeniable fact. Science, medicine, agriculture, energy, and many industries would hardly have managed without radioactive isotopes. But when a peaceful atom becomes uncontrollable or becomes a weapon, it is a threat to the existence of our entire planet.