The process of transmutation is nothing but the conversion of any nuclide into another one with some specific change in number of neutrons in the final nucleus. Transmutation can be achieved either by nuclear or even by radioactive decay. In a fusion reaction the transmutation induced by neutron involves the processes of material activation, tritium breeding.
This might also give fission fuel breeding or nuclear waste transmutation. During such changes, the material activation is very important as the activation products might give radiated particles like alpha, beta and gamma rays. These particles poses potential radioactive hazards to all kinds of living organisms and overall environment.
What is Transmutation?Back to Top
Each element has definitive number of protons in nuclei and in case one element changes into another, a change in number of nuclear protons is also observed. This happens naturally in many element’s nuclides and is induced in almost any nuclide by proton bombardment. This leads to instability in nucleus and leads to transmutation of element.
The neutron induced reactions are important as far as transmutations are concerned. But we need to understand that not every types of neutron nuclear reaction can induce transmutations as not every reaction can bring about changes in protons or neutrons numbers in nucleus. These are triggered by neutron nuclear reactions which finally induce the transmutation. These changes are brought in whenever or wherever there is a conversion of one nuclide into another. Radioactive decay is another method of inducing the process of transmutation.
In some cases of long chain or multiple chain transmutation processes the neutron nuclear reactions and radioactive decays are combined together. Transmutation chain is basically used for representing the transformation of nuclides during transmutation processes.
Natural radioactive decay can take place mainly in elements with higher nuclear charge numbers (higher than 83) as the presence of huge number of positive charges makes the nucleus very unstable. This leads to decay process and all individual components of nucleus are emitted. As the nucleus contains both protons and neutrons the radioactive decay involve emission of protons and neutrons during transmutation. But as complimentary transformations even electrons or positrons are also emitted.
Chemical Transmutation DefinitionBack to Top
Radioactive emissions of atoms in form of electromagnetic radiation results from natural or artificial nuclear transmutation. All three forms of radiation (alpha, gamma and beta) results from either natural or man-made sources. These occurs only from heavy elements nuclei. When alpha particles are emitted along with some beta particles from an elements atom, the atomic number is changed as well. This brings about fundamental properties of the element as well.
These changes in properties are mainly due to changes in nuclei and this brings about a chemical characteristics as well. Hence the chemical transmutation is considered for such reactions. A transmutation in which the nuclei of large atom disintegrate or transmute into nuclei of smaller atoms or when nuclei of smaller elements combine to form a larger nuclei, it always involve the chemical change as well.
Natural TransmutationBack to Top
Transmutation is a nuclear reaction when changes within nuclei brings about a changes in atom brings about changes in the overall characteristics of the atom. These changes can be either natural or man-made. Natural transmutation occurs when a single unstable radioactive nucleus spontaneously breaks down or decays into by emitting particles. There are several forms of decays and most of these give out alpha decay, beta decay or simply positron emissions under natural decay or transmutations.
Natural transmutation is different from artificial one as in the latter case it is intentionally carried out by bombarding an atom with high speed particle which results in change in atomic characteristics.
238U92 (alpha emitter) $\rightarrow$ 4He2 (alpha particle emitted) +234Th90 (new atom)
|Characteristics||Radioactive atom (Uranium)||New atom (Thorium)|
|Proton number||92||90 (decrease by 2)|
|Number of neutron||146||144 (decrease by 2)|
Transmutation ReactionBack to Top
Any transmutation reaction is a nuclear reaction where a nuclide of an element is changed into another by either artificial means or occurs spontaneously. To bring about a transmutation reaction, bombarding a target atom with fast moving particles is carried out. The target atom usually is a stable form and it finally gives out two products. A daughter nuclei and either a neutron or proton are formed.
14N7 + 4α2 $\rightarrow$ 17O8 + 1P1
Transmutation Chemistry ExampleBack to Top
There are several forms of transmutation reactions where either a gamma or alpha or beta particles are released when decay reaction takes place. But the main decay types are as follows which are mainstay of any transmutation reaction.
|Beta-||Spontaneous decay and emission of beta|
|Beta+||Spontaneous decay and emission of beta+|
|Alpha||Spontaneous decay and emits alpha|
|Beta- alpha||Spontaneous decay and beta- and alpha are emitted|
Transmutation Chemistry Equations
The transmutation equations always involves two reactants and two products. The reactants are stable atom and one bombarding particle. Once the bombardment takes place the products come out as either positron, proton or neutron along with a daughter nuclei.
238U92 $\rightarrow$ 234Th90 + 4He2
131I53 $\rightarrow$ 131Xe54 + 0e-1