S and P Block Elements
IIT JEE AIEEE S and P Block Elements Study Material - Course Material
The outermost orbital of s block elements consists of one or two electrons. Next to the outer most penultimate shell has either 2 or 8 electrons. s-block elements show a fixed valency which depends on the number of electrons present in the outermost shell.
Except hydrogen , all s-block elements have low values of ionisation potential decreases in the case of alkali metals and alkaline earth metals as the atomic number increases. Ionisation potential increases on moving horizontally from IA to IIA. On account of low values of ionisation potentials , these elements are highly electropositve , i.e., easily lose valency electrons and form cations.
The elements of groups of p block elements exhibit a range of properties. Many of the trends observed in this group can be understood from considerations of their electron configurations and their respective positions in the periodic table. For example, the inert pair of valence-shell electrons retained in the Ti+ ion is also found in several other cations following a transition series.