Question

How do we classify elements?(please give a proper answer that can be written in a board paper)

Answer 1

Elements are classified into Metals, Non-metals and Metalloids

The elements (e.g., silicon, germanium, arsenic, antimony and tellurium) bordering this line and running diagonally across the Periodic Table show properties that are characteristic of both metals and nonmetals. These elements are called Semi-metals or Metalloid

The elements present on theleft side of metalloids are metals, and the elements present on the right side of the metalloids are non metals.

Elements are also classified based on the electronic configuration as s,p,d, and f block .
The elements of Group 1 (alkali metals) and Group 2 (alkaline earth metals) which have ns1 and ns2 outermost electronic configuration belong to the s-Block Elements.

The p-Block Elements comprise those belonging to Group 13 to 18 and these together with the s-Block Elements are called the Representative Elements or Main Group Elements.

the elements of Group 3 to 12 in the centre of the Periodic Table. These are characterised by the filling of inner d orbitals by electrons and are therefore referred to as d-Block Elements. These elements have the general outer electronic configuration (n-1)d 1-10ns0-2

The two rows of elements at the bottom of the Periodic Table, called the Lanthanoids, Ce(Z = 58) – Lu(Z = 71) and Actinoids, Th(Z = 90) – Lr (Z = 103) are characterised by the outer electronic configuration (n-2)f 1-14 (n-1)d 0–1 ns2 . The last electron added to each element is filled in f- orbital. These two series of elements are hence called the InnerTransition Elements (f-Block Elements).