Reaccion nuclear (1)

Reacción nuclear:

In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomicparticle (such as a proton, or high energy electron) from outside the atom, collide to produce products different from the initial particles. In principle, a reaction can involve more than three particlescolliding, but because the probability of three or more nuclei to meet at the same time at the same place is much less than for two nuclei, such an event is exceptionally rare. Radioactive decays canbe considered to be spontaneous nuclear reactions, in as much as there is such a thing as a spontaneous chemical reaction. However, "nuclear reaction" is a term usually implying an induced type ofnuclear reactions, where two particles initially react, and is generally not applied to radioactive decay.
If particles collide and separate without changing, the process is called an elastic collisionrather than a reaction.

In the symbolic figure shown to the right, 6
3Li and deuterium (2
1H) react to form the highly excited intermediate nucleus 8
4Be which then decays immediately into twoalpha particles. Protons are symbolically represented by red spheres, and neutrons by blue spheres.
6
3Li + 2
1H → 4
2He + ?
To balance the equation above, the second nucleus to the rightmust have atomic number 2 and mass number 4; it is therefore also helium-4. The complete equation therefore reads:
6
3Li + 2
1H → 4
2He + 4
2He
or more simply:
6
3Li + 2
1H → 2 4
2HeNatural nuclear reactions occur in the interaction between cosmic rays and matter, and just as with certain radioactive decays (for example the alpha decay of Plutonium in a RadioisotopeThermoelectric Generator), nuclear reactions can be employed artificially to obtain nuclear energy, at an adjustable rate, on demand. Perhaps the most notable nuclear reactions are the nuclear chain reaction...