Atoms can gain or lose energy when an electron moves from a higher orbit to a lower orbit around the nucleus. However, splitting the nucleus of an atom will release much more energy than the energy when electrons return to a lower orbit from a higher orbit. That energy can be used for destructive purposes or for safe and productive purposes. Splitting an atom is called nuclear fission, a process discovered in 1938; The repeated splitting of atoms in fission is called a chain reaction. While many people don't have the equipment to do this, if you're curious about the splitting process, here's a summary.
Step
Part 1 of 2: Basic Atomic Fission
Step 1. Choose the right isotope
Some elements or their isotopes undergo radioactive decay. However, not all isotopes are created equal in terms of their ease of cleavage. The most frequently used isotope of uranium, has an atomic weight of 238, consisting of 92 protons and 146 neutrons, but its nucleus tends to absorb neutrons without splitting into the smaller nuclei of other elements. An isotope of uranium that has three fewer neutrons, 235U, can be much easier to cleave than isotopes 238U; Such isotopes are called fissile materials.
Some isotopes can be cleaved very easily, so rapidly that a continuous fission reaction cannot be maintained. This is called spontaneous fission; plutonium isotope 240Pu is an example of that isotope, unlike the isotope 239Pu with a slower fission rate.
Step 2. Obtain enough isotopes to ensure that fission will continue after the first atom splits
This requires a certain minimal amount of isotopic material to be split open for the fission reaction to take place; This amount is called the critical mass. Gaining critical mass requires source material for the isotope, to increase the chances of fission occurring.
Sometimes, it is necessary to increase the relative amount of split isotope material in the sample to ensure that a continuous fission reaction can occur. This is called enrichment, and there are several methods used to enrich a sample. (For the methods used to enrich uranium, see the wikiHow How to Enrich Uranium.)
Step 3. Shoot the nucleus of the split isotope material with subatomic particles repeatedly
Single subatomic particles can hit atoms 235U, splitting it into two separate atoms of another element and releasing three neutrons. These three types of subatomic particles are often used.
- Proton. These subatomic particles have mass and a positive charge. The number of protons in an atom determines the element of the atom.
- Neutrons. These subatomic particles have mass as protons but have no charge.
- Alpha particles. This particle is the nucleus of the helium atom, part of the electrons that revolve around it. This particle consists of two protons and two neutrons.
Part 2 of 2: Atomic Fission Method
Step 1. Shoot one atomic nucleus (nucleus) of the same isotope at another
Because tenuous subatomic particles are difficult to pass through, a force is often required to force the particles out of their atoms. One method of doing this is to shoot atoms of a given isotope at other atoms of the same isotope.
This method was used to create the atomic bomb 235U dropped on Hiroshima. Weapons such as guns with uranium cores, which shoot atoms 235U on atom 235Another U, carries the material at such high speed that it causes the released neutrons to hit the nucleus of the atom 235another U and destroy it. The neutrons released when an atom splits can take turns hitting and splitting the atom 235other U.
Step 2. Squeeze the atomic sample tightly, bringing the atomic material closer together
Sometimes, the atoms decay too fast to be fired at each other. In this case, bringing the atoms closer together increases the chances of the freed subatomic particles hitting and splitting other atoms.
This method was used to create the atomic bomb 239Pu dropped on Nagasaki. Ordinary explosions surround the mass of plutonium; when detonated, the explosion propels the mass of plutonium, carrying the atoms 239Pu approaches so that the released neutrons will continue to hit and split atoms 239other pu.
Step 3. Excite the electrons with a laser beam
With the development of the petawatt laser (1015 watts), it is now possible to split atoms using a laser beam to excite the electrons in the metal encasing the radioactive substance.
- In a 2000 test at Lawrence Livermore Laboratory in California, uranium was wrapped in gold and placed in a copper crucible. A pulse of infrared laser beam of 260 joules hits the envelope and housing, exciting the electrons. As the electrons return to their normal orbits, they release high-energy gamma radiation that penetrates the gold and copper nuclei, releasing neutrons that penetrate the uranium atoms beneath the gold layer and split them apart. (Both gold and copper became radioactive as a result of the experiment.)
- Similar tests were carried out at the Rutherford Appleton Laboratory in the United Kingdom using 50 terawatts (5 x 1012 watts) laser aimed at a tantalum plate with various materials behind it: potassium, silver, zinc, and uranium. Part of the atoms of all these materials was successfully split.
Warning
- In addition to certain fissions of certain isotopes that are too fast, smaller explosions can destroy the fissionable material before the explosion reaches the expected sustained reaction rate.
- As with any equipment, follow the required safety procedures, and don't do anything that seems risky. Be careful.
