Curium (96Cm) is an artificial element with an atomic number of 96.
Because it is an artificial element, a standard atomic weight cannot be given, and it has no stable isotopes.
The longest-lived isotope is 247Cm, with half-life 15.6 million years – orders of magnitude longer than that of any known isotope beyond curium, and long enough to study as a possible extinct radionuclide that would be produced by the r-process.
[2][3] The longest-lived known isomer is 246mCm with a half-life of 1.12 seconds.
No fission products have a half-lifein the range of 100 a–210 ka ... ... nor beyond 15.7 Ma[9]