Nuclear Chemistry

Nuclide Synthesis

Nuclides can be synthesized artificially. The conversion of one nuclide into another nuclide is called transmutation.

Conversion of one nuclide into another nuclide is called transmutation. Transmutation occurs naturally when unstable nuclei break down into other, smaller nuclei over time, releasing particles and/or energy during radioactive decay. Radioactive decay is not the only process that leads to transmutation. It is possible to form new nuclides artificially, through bombardment of an existing nuclide with another nuclide or a neutron.

The first such successful experiment was performed by British scientist Ernest Rutherford in 1911. Rutherford bombarded nitrogen with alpha particles, particles identical to a helium ion (He2+) consisting of two protons and two neutrons, and obtained oxygen-17 and hydrogen.
714N+24He817O+11H{}_{\,\,7}^{14}\rm {N}+{}_2^4{\rm{He}}\rightarrow{}_{\,\,8}^{17}{\rm O+{}_1^1\rm {H}}
Transmutation reactions typically require high amounts of energy. In modern physics and chemistry, transmutation reactions often take place in particle accelerators. A particle accelerator is a large construction that uses electromagnetic fields to accelerate particles to relativistic speeds. CERN's Large Hadron Collider in Switzerland and Fermilab's various accelerators near Chicago are examples of particle accelerators.

The heaviest element found in nature is uranium, which has an atomic number of 92. Elements with a higher atomic number than uranium are transmuted artificially using particle accelerators. An element with a higher atomic number than that of uranium is sometimes called a transuranium element.

A significant transuranium element is plutonium, with the atomic number 94. Plutonium can form in nuclear reactions, through a series of reactions. First, uranium-238 undergoes neutron bombardment and forms uranium-239.
92238U+01n92239U{}_{\,\,92}^{238}\rm {U}+{}_0^1\rm {n}\rightarrow{}_{\,\,92}^{239}\rm {U}
Uranium-239 is not stable, and undergoes beta decay, to form neptunium-239.
92239U93239Np+10e{}_{\,\,\,92}^{239}\rm {U}\rightarrow{}_{\,\,\,93}^{239}{\rm{Np}}+{}_{-1}^{\;\,\,0}\rm {e}
Neptunium-239 is also unstable and undergoes beta decay to form plutonium-239, which is stable.
This reaction is important because plutonium-239 can be used to build nuclear bombs.