Hydrochloric acid attacks all metals but most are
slightly affected by nitric acid owing to the formation of protective oxide
layers; alkalies have no action The magnetic properties of the actinoids are more complex than those
of the lanthanoids Although the variation in the magnetic susceptibility
of the actinoids with the number of unpaired 5 f electrons is roughly
parallel to the corresponding results for the lanthanoids, the latter have
higher values It is evident from the behaviour of the actinoids that the ionisation
enthalpies of the early actinoids, though not accurately known, but are
lower than for the early lanthanoids