But in reality always told us little, or perhaps only as far as they were concerned that supiesemos.En this article, try to give a snapshot that may help us understand the importance with which this energy is present in our lives. All matter is made up of atoms are so small that the head of a pin fit 60 billion of them are some of the different physical and chemical properties, such as hydrogen, carbon, oxygen, iron etc. Of which matter is formed and therefore the animal, vegetable, mineral and of course us humans. Atoms consist of a core of particles called protons and neutrons, turning around, there are the special conditions electrones.Bajo the nucleus of an atom can absorb a neutron low-energy part of the merger is releasing an extra neutron high energy collide with other nuclei creating the “Chain Reaction”, this large number of fissions an amount of heat released in a controlled manner is used in our nuclear power plants, and this is where we start talking about the radioactivity due to We are accustomed to associate nuclear power plants and nuclear weapons with that word. In reality, the radioactivity was before life began in the universe, that has different sources of different intensities some from the cosmos, some of the sun, the earth itself, our homes and streets contain small amounts of radioactivity from potassium 40, uranium-238 , thorium-232, our own body contains carbon 14, potassium 40 and others, which constitute 69% of the annual dose of radioactivity absorbed by any inhabitant of the earth by the mere fact habitarla.El where we live greatly influences the index, a person living at 2000 meters above sea level, receives three times more cosmic radiation than someone living in a coastal city, where travel by plane you are exposed to 150 times higher doses of cosmic radiation at the level of mar.Por it, without knowing or feel of these sources our body gets 82% of the annual dose of radiation.