We explain what a neutron is, how it was discovered, its function and properties. Also, what is nuclear fission and what is it used for?
What is a neutron?
a neutron It is a type of subatomic particle (particles that make up the atoms of matter) present in the nucleus of some atoms and endowed with a neutral electrical charge. All atoms in the universe are made up of neutrons, protons (positive electrical charge) and electrons (negative electrical charge).
The neutrons are found in the nucleus of atoms (except hydrogen), along with protons. They are held together by strong nuclear forces, while the electrons, in the classical atomic model, dance around in different orbits. For this reason, protons and neutrons are known as nucleons.
Discovery of the neutron
Before the discovery of neutrons, there was a mystery regarding the mass and charge of atoms, especially when it became evident that electrons could not be in the atomic nucleus, but that the nuclear mass did not correspond exactly to the total mass of the protons.
Thus, the German physicist Ernest Rutherford, who discovered protons, proposed in 1920 the need for a neutron to exist that is, a particle that would provide mass to the atom without modifying its electrical charge.
Years later, neutrons were discovered in 1932 by the English physicist James Chadwick winner of the 1935 Nobel Prize in Physics. Thanks to different experiences and studies of the radiation obtained by striking paraffin or other hydrogen-rich compounds, Chadwick demonstrated that the physical predictions did not correspond to the observed phenomenon.
That is to say that the radiation obtained came from particles similar to the proton, but that did not have an electrical charge. That was the first experience that led to the formal discovery of neutrons.
Properties of neutrons
The neutrons have a mass similar to that of the proton but slightly larger (1.00137 times) and, therefore, much larger than that of the electron (1838.5 times). Like protons, are composed of fundamental particles called quarks. Neutrons have two quarks.down” (below) and one “up” (above). The sum of the charges of these quarks is zero.
When found in the atomic nucleus, neutrons are stable, but when found outside, in a free state, they have a half-life of 879.4 seconds, before decaying into a proton, an electron and an electron antineutrino. This is what often happens inside nuclear plants, where there is a high concentration of free neutrons.
Function of neutrons
The neutrons perform a stabilizing function within the nucleus of the atom. If they were not there, the protons would repel each other. With their presence, neutrons compensate for this repulsive electrical force through the strong nuclear force that keeps protons and neutrons in the nucleus.
However, free neutrons can be used for other types of functions, convenient for humans. For example, used for penetration and visualization of materials through its controlled emission.
They are also used in nuclear fission, that is, the breakdown of the atomic nucleus by bombarding it with free neutrons, thus causing reactions that release a huge amount of energy. This, of course, entails many dangers, since the uncontrolled emission of neutrons can damage the structure of the basic proteins of living beings.
Nuclear fission
nuclear fission It is a form of atom breakdown specifically atoms of heavy materials such as uranium (U) and its stable isotopes.
This procedure consists of bombarding the nucleus of, for example and most commonly, uranium with fast neutrons which causes its splitting and the release of energy, and along with it new free neutrons, in a chain reaction capable of generating high levels of usable energy.
When this reaction occurs in a controlled environment, can be used to generate electricity through turbines and put it to human use, just as happens inside nuclear plants. Nuclear energy is relatively safe and quite profitable, but it entails certain risks since it underproduces toxic (radioactive) elements.
On the contrary, When this reaction occurs uncontrolled, we are in the presence of an atomic bomb one of the most destructive war inventions that human beings have been able to conceive, just like those dropped by the American government on the Japanese cities of Hiroshima and Nagasaki in World War II.
Continue with: Antimatter
References
- “Neutron” on Wikipedia.
- “The Neutron turns 80” in VERY Interesting.
- “The neutrons” on Astrojem.com.
- “The neutron is the perfect probe to study materials” in Tendencias21.
- “The Neutron” in Hyperphysics at Georgia State University (USA).
- “Neutron (Subatomic particle)” in The Encyclopaedia Britannica.