P-Block Elements and Electronic Configuration

P-Block Elements

• The last electron in p-block elements enters the outermost p orbital, and since there are three p orbitals, a maximum of six electrons can be accommodated.
• There are six groups of p-block elements in the periodic table, numbered from 13 to 18, with boron, carbon, nitrogen, oxygen, fluorine, and helium as the heading elements.
• The valence shell electronic configuration of p-block elements is ns2 np1-6, except for helium.

Electronic Configuration and Properties

• The difference in the inner core of elements greatly influences their physical properties, such as atomic and ionic radii, ionisation enthalpy, etc.
• The maximum oxidation state shown by a p-block element is equal to the total number of valence electrons.

Oxidation States

• P-block elements may show other oxidation states that differ from the total number of valence electrons by units of two.
• The group oxidation state is the most stable state for the lighter elements in each group.
• The oxidation state two units less than the group oxidation state becomes progressively more stable for the heavier elements in each group.

Inert Pair Effect

• The occurrence of oxidation states two units less than the group oxidation states is sometimes attributed to the ‘inert pair effect’.

Metals and Non-Metals

• Non-metals and metalloids exist only in the p-block of the periodic table.
• The non-metallic character of elements decreases down the group.
• The heaviest element in each p-block group is the most metallic in nature.

Compounds and Reactivity

• Non-metals have higher ionisation enthalpies and higher electronegativities than metals.
• Compounds formed by highly reactive non-metals with highly reactive metals are generally ionic.
• Compounds formed between non-metals themselves are largely covalent in character.

Oxides

• The non-metal oxides are acidic or neutral, whereas metal oxides are basic in nature.

First Member of P-Block

• The first member of p-block differs from the remaining members of their corresponding group in two major respects: size and the effect of d-orbitals in the valence shell.
• The second period elements of p-groups have a maximum covalence of four, whereas the third period elements can expand their covalence using d-orbitals.