It is a nuclear reaction since a change has occurred in the nucleus. In nuclear reactions the particles in the nucleus are changed and one element is transformed into another element when particles in the nucleus gained are lost. Unlike chemical reactions which involve the electrons in an atom, nuclear reaction involve the nucleus. A nuclear reaction may be a nuclear fission or nuclear fusion; An example of nuclear reaction is where two isotopes of hydrogen (tritium and deuterium) are fused together under high pressure and temperature, to form a more stable atom of helium. This is an example of nuclear fusion reaction.
Because the concentration of molecules in the gas phase increases with increasing pressure, the concentration of dissolved gas molecules in the solution at equilibrium is also higher at higher pressures
