Isotopes 54 Radiochemistry 34 Geochemistry 12 Physical chemistry 11 Soil science 11 Agricultural chemistry 10 Biochemistry 10 Catalysis 10 Chemistry 10 Ionisation 9 Photo chemistry 7 Earth sciences 6 Isotope geology 6 THE INTERNATIONAL JOURNAL OF APPLIED RADIATION AND ISOTOPES (J) 6 Radio chemistry 5 ISOTOPES 4 Photochemistry 4 Radiation 4 isotopes 4 Atomic nucleus 3 Climatic changes 3 Genomics 3 Nuclear chemistry 3 Organic reaction mechanisms 3 Physical Chemistry 3 Plant physiology 3 Radioactivity 3 Radiobiology-- Biophysics-- Biology 3 Archaeology 2 Biology 2