p – Block Elements

Syllabus:
  ü  Group 15 Elements:
Ø  General Introduction, Electronic Configuration, Occurrence, Oxidation  States
Ø  Trends in Physical and Chemical Properties 
Ø  Nitrogen Preparation Properties and Uses

Ø  Compounds of Nitrogen: Preparation and Properties of Ammonia and    Nitric Acid. 
  ü  Group 16 Elements:
Ø  General introduction: Electronic Configuration, Oxidation States, Occurrence
Ø  Trends in Physical and Chemical Properties
·       Dioxygen: Preparation, Properties and Uses, Classification Of Oxides
Ø  Ozone
·       Sulphur: Allotropic Forms, Compounds of Sulphur
Ø  Preparation Properties and Uses of Sulphur-Dioxide
Ø  Sulphuric Acid: Industrial Process of Manufacture, Properties and Uses
Ø  Oxoacids of Sulphur (Structures Only).

  ü  Group 17 Elements
Ø  General introduction, electronic configuration, oxidation states, occurrence
Ø  Trends in physical and chemical properties; compounds of halogens
Ø  Preparation, properties and uses of Chlorine and Hydrochloric acid
Ø  Interhalogen compounds, Oxoacids of halogens (structures only).

  ü  Group 18 Elements
Ø  General introduction, electronic configuration, occurrence
Ø  Trends in physical and chemical properties, uses.
  





  

The elements in which the last electron enters in the valence p-sub shell are called the p-block elements. They include elements from groups 13 to 18. Their general electronic configuration is ns2np1-6 where n = 2 (except He which has 1s2 configuration). They, includes metals, non-metals and metalloids.

F Elements belonging to the s and p-blocks in the periodic table are called the representative elements or main group elements.
F Inert pair effect:  The tendency of ns2 electron pair to participate in bond formation decreases with the increase in atomic size. Within a group the higher oxidation state becomes less stable with respect to the lower oxidation state as the atomic number increases. This trend is called ‘inert pair effect’. In other words, the energy required to unpair the electrons is more than energy released in the formation of two additional bonds.


Group 16 Elements
Group 16 includes oxygen (O), sulphur (S), selenium (Se), tellurium (Te) and polonium (Po). They are also called chalcogens (means ore producing). Oxygen and sulphur are non-metals, selenium and tellurium are metalloids, while polonium is a radioactive metal.
The general valence shell electronic configuration of these elements is ns2np4.