From the Unity of Nature's Elements in Empedocles to a ...

____ 52. The group of 14 elements in the sixth period that have occupied 4f orbitals is the. a. actinides. c. transition elements. b. lanthanides. d. metalloids. ____ 53. Within the p-block elements, the elements at the top of the table, compared with those at the bottom, a. have larger radii. c. have lower ionization energies. b. are more ... ................
................