metals. They mostly form coloured ions, exhibit variable valence (oxidation states), paramagnetism and oftenly used as catalysts. However, Zn, Cd and Hg which have the electronic configuration, ( n- ) d ns do not show most of the properties of transition elements. In a way, transition metals form a bridge between the chemically active metals of s- block elements and the less active elements of Groups and and thus take their familiar name “Transition Elements” .
. . The f-Block Elements (Inner-Transition Elements) The two rows of elements at the bottom of the Periodic Table, called the Lanthanoids, Ce( Z = ) – Lu( Z = ) and Actinoids , Th( Z = ) – Lr ( Z = ) are characterised by the outer electronic configuration ( n - ) f - ( n - ) d – ns . The last electron added to each element is filled in f- orbital.
These two series of elements are hence called the Inner- Transition Elements ( f- Block Elements ). They are all metals. Within each series, the properties of the elements are quite similar. The chemistry of the early actinoids is more complicated than the corresponding lanthanoids, due to the large number of oxidation states possible for these actinoid elements.
Actinoid elements are radioactive. Many of the actinoid elements have been made only in nanogram quantities or even less by nuclear reactions and their chemistry is not fully studied. The elements after uranium are called Transuranium Elements . Problem .
The elements Z = and have not yet been discovered. In which family/group would you place these elements and also give the electronic configuration in each case. We see from Fig. .
, that element with Z = , would belong to the halogen family (Group ) and the electronic configuration would be [Rn] f d s p . The element with Z = , will be placed in Group (alkaline earth metals), and will have the electronic configuration [Uuo] s . . .
Metals, Non-metals