Process by which the relative frequency of an isotopeAtoms of the same atomic number (i.e. the same chemical elem... in an elementChemical base material which cannot be chemically converted ... is increased. Example: enrichmentProcess by which the share of a certain isotpe in an element... of uraniumNatural radioactive element with the atomic number 92. The n... at the uranium-235 isotopeAtoms of the same atomic number (i.e. the same chemical elem...; See ‘Enriched uranium’.