CBSE Class 11-science Chemistry The p-Block Elements
Introduction to p- Block ElementsHighest oxidation state of p block elements is equal to total no. of valence electrons.
Of the group 13 elements, only Boron forms covalent compounds while all others form ionic compounds.
Inert pair effect becomes predominant on going down the group.
Properties of BoronThe first member of each group of p block differs in many respects from the other members of the group on account of its small size and absence of vacant d-orbitals.
Boron is the first element of group 13. So, it also differs from rest of the elements.
Boron is extremely hard and has a very high melting point. It shows diagonal relationship with Silicon.
Compounds of p- Block ElementsBorax is the most important compound of Boron. It is used to detect the basic radicals present in a salt.
Boric acid is a mild acid often used as an antiseptic, insecticide and a flame retardant.
The simplest compound formed between Boron and hydrogen is Diborane.
Aluminium reacts with all mineral acids except Nitric acid.
Group 14 ElementsGroup 14 belongs to p- block of the periodic table and the first element of this group is carbon.
As we go move from top to bottom in group 14 metallic character increases.
The atomic and ionic radii increase on moving down the group from carbon to lead.
Allotropes of CarbonCarbon has strong catenation tendency.
Due to catenation and multiple bond formation carbon shows a number of allotropic forms like graphite, diamond, and fullerenes, carbon black, charcoal and coke.
Carbon remains unaffected by water and dilute acids and reacts with hot concentrated acids and halogens.
Silicon and Its CompoundsSilicon is a shiny, blue-gray non metal having semi conducting properties.
Silicates are complex network solids with the basic structural unit as silicate ion.