NUCLEAR CHEMISTRY

Nuclear chemistry is a subfield of chemistry dealing with radioactivity, nuclear processes and nuclear properties. It heavily overlaps with fields like nuclear physics, particle physics and quantum electrodynamics.

It is the chemistry of radioactive elements such as the actinides, radium and radon, together with the chemistry associated with equipment (such as nuclear reactors) which are designed to perform nuclear processes. This includes the corrosion of surfaces and the behaviour under conditions of both normal and abnormal operation (such as during an accident). It also deals with the behavior of objects and materials after being placed into a waste store or otherwise disposed of.

It involves the study of the production and use of radioactive sources for a range of processes like:

-Radiotherapy in medical applications -Radioactive tracers within industry, science and the

environment - The use of radiation to modify materials. (like in the

case of polymers).

-The study and use of nuclear processes in non-radioactive areas of human activity.

For instance, nuclear magnetic resonance (NMR) spectroscopy is commonly used in synthetic organic chemistry and physical chemistry and for structural analysis in macromolecular chemistry.

A combination of radiochemistry and radiation chemistry is used to study nuclear reactions such as fission and fusion.

This is clearly important as nuclear processes are of superb relevance in the present time.

For example for for the particular case of lithium (6) and tritium fusion reaction:

Li-9 + H-3 → 2 He -4 + energy.

Kinetic energy will be released during the course of a reaction .This can be calculated by reference to a table of very accurate particle rest masses (see http://physics.nist.gov/PhysRefData/Compositions/index.html), as follows. According to the reference tables, the Lithium9 nucleus has a relative atomic mass of 6.015 atomic mass units (abbreviated u), the tritium has 2.014 u, and the helium-4 nucleus has 4.0026 u Thus:

* Total rest mass on left side = 6.015 + 2.014 = 8.029 u * Total rest mass on right side = 2 × 4.0026 = 8.0052 u * Missing rest mass = 8.029 - 8.0052 = 0.0238 atomic mass units.

In a nuclear reaction, the total (relativistic) energy is conserved. The "missing" rest mass must therefore reappear as kinetic energy released in the reaction; its source is the nuclear binding energy. Using Einstein's mass-energy equivalence formula E = mc², the amount of energy released can be determined. We first need the energy equivalent of one atomic mass unit:

1 u c2 = (1.66054 × 10-27 kg) × (2.99792 × 108 m/s)2 = 1.49242 × 10-10 kg (m/s)2 = 1.49242 × 10-10 J (Joule) × (1 MeV / 1.60218 × 10-13 J) = 931.49 MeV,

so 1 u c2 = 931.49 MeV.

Hence, the energy released is 0.0238 × 931 MeV = 22.4 MeV.

Expressed differently: the mass is reduced by 0.3 %. The energy density for kg of material created is of 90 x1015J/kg (90PJ/kg)And for comparison the energy density of TNT is 4.6 x106 J/kg (4.6 MJ/kg)

and for dynamite is approximately 7.5 x106 J/kg ( 7.5 MJ/kg) .