. General trends in properties of p-block elements: We already learnt that the properties of elements largely depends on their electronic configuration, size, ionisation enthalpy, electronegativity etc... Let us discuss the general trend in such properties of various p-block elements. .
. Electronic configuration and oxidation state: The p-block elements have a general electronic configuration of ns , np - . The elements of each group have similar outer shell electronic configuration and differ only in the value of n (principal quantum number). The elements of group (inert gases) have completely filled p orbitals, hence they are more stable and have least reactivity.
The elements of this block show variable oxidation state and their highest oxidation state (group oxidation state) is equal to the total number of valance electrons present in them. Unlike s-block elements which show only positive oxidation state, some of the p-block elements show negative oxidation states also. The halogens have a strong tendency to gain an electron to give a stable halide ion with completely filled electronic configuration and hence - oxidation state is more common in halogens. Similarly, the other elements belonging to pnictogen and chalcogen groups also show negative oxidation states.
Evaluate yourself : Why group elements are called inert gases? Write the general electronic configuraton of group elements - - - - Table . General electronic configurations and oxidation states of p-block elements Group No. Group Name Icosagens Tetragens Pnictogens Chalcogens Halogens Inert gases General outer electronic configuration ns np ns np ns np ns np ns np ns np Highest oxidation state (Group oxidation state) + + + + + + Other observed oxidation states + + , - + , - + , + , - + , + , + , - + .
+ , + . . Metallic nature: The tendency of an element to form a cation by loosing electrons is known as electropositive or metallic character. This character depends on the ionisation energy.
Generally on descending a group the ionisation