are: the fourteen chemical elements with atomic numbers in the range 89-102 inclusive (i.e. from actinium to nobelium). [P8.4]
are all: radioactive. [P9.3]
include: uranium and plutonium. [P8.4]
occur: in a part of the periodic table where the 5f subshell of atoms in their ground state is being progressively filled. [P8.4]
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