Isotopes may be used.Logical formLearned from8 sentences. Some isotopes can be constituted-of-or-filled-with radium.Logical formLearned from8 sentences. Isotopes can be constituted-of-or-filled-with samarium.Logical formLearned from8 sentences. A radioactive isotope can be short-lived.Logical formLearned from8 sentences. Stable isotopes can be constituted-of-or-filled-with hydrogen.Logical formLearned from8 sentences. A shortage of medical isotopes may cause delays to examinations.Logical formLearned from8 sentences. An isotope may be needed for nuclear fission.Logical formLearned from8 sentences. Changes can be in (isotope ratios).Logical formLearned from8 sentences. A type of (oxygen isotope) may depend on temperature.Logical formLearned from8 sentences. Isotopes can be forms.Logical formLearned from8 sentences. Isotopes may act as clocks.Logical formLearned from8 sentences. Limits can be in isotopes.Logical formLearned from8 sentences. A history may be written/wrote in isotopes.Logical formLearned from8 sentences. An isotope may undergo an abundance.Logical formLearned from8 sentences. Isotopes may show_up in hair.Logical formLearned from8 sentences.