actinium

As nouns the difference between actinium and praseodymium

is that actinium is chemical element actinium (atomic number 89) while praseodymium is a metallic chemical element (symbol pr) with an atomic number of 59.

As nouns the difference between praeseodymium and actinium

is that praeseodymium is while actinium is chemical element actinium (atomic number 89).

As nouns the difference between actinium and ionium

is that actinium is chemical element actinium (atomic number 89) while ionium is (physics|dated) a supposed decomposition-product of actinium once thought to be the source of radium.

As a noun actinium

is chemical element actinium (atomic number 89).

As an adjective actiniferous is

containing or producing actinium.

As nouns the difference between actinium and mesothorium

is that actinium is chemical element actinium (atomic number 89) while mesothorium is (physics) any product of the radioactive decay of thorium, mainly isotopes of radium and actinium.