- Bulk actinoid hydrides are only known in this form.
- In addition there are smaller quantities of other actinoids, created when one isotope is transmuted into another by a reaction involving neutron capture.
- The actinoid elements in this case consist primarily of the largely unconsumed remains of the original fuel ( typically U-238 and other isotopes of uranium ).
- Metals in the " f "-block ( the actinoids ) can accommodate higher coordination number due to their greater ionic radii and availability of more orbitals for bonding.
- The "'actinide "'or "'actinoid "'( IUPAC nomenclature ) series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.