<page_title> Isotopes of thorium </page_title> <section_title> List of isotopes </section_title> <table> <cell> 228Th <col_header> nuclide symbol </col_header> <col_header> excitation energy </col_header> </cell> <cell> 1.9116(16) y <col_header> half-life </col_header> </cell> </table>
228Th has a half-life of 1.9116 years.