Periodicity | Types of Elements#

Based on electronic configuration, elements have been classified into four broad types: s-block, p-block, d-block and f-block.

s-block elements#

Group 1 and group 2 elements in the periodic table are known as s-block elements.
Group 1 elements are known as Alkali metals while group 2 elements are known as Alkaline earth metals.
General Valence Shell Electronic Configuration of s-block elements is ns^1-2
They have low ionization enthalpy and react very quickly to form ions. Alkali metals lose 1 electron and alkaline earth metals lose 2 electrons to form ions.
Reactivity increases down the group because valence electrons get farther away from nucleus as we go down the group and force of attraction between valence electrons and nucleus decreases as we go down the group.

Group 13 to group 18 elements are known as p-block elements.
Group 18 elements are known as noble gases because they show very less reactivity.
Group 17 elements are known as halogens and group 16 elements are known as chalcogens.
General valence shell electronic configuration of p-block elements is ns²np^1-6.
Group 16 and group 17 elements have high electron gain enthalpy because they readily gain one or two electrons to achieve noble gas configuration.
Non-metallic character increases as we move from left to right in a period and metallic character increases as we go down the group.

d-block elements are also known as transition elements because they lie between s-block and p-block elements and form a bridge between them.
General valence shell electronic configuration: (n-1)d^1-10ns^0-2
Transition elements are all metals.
Generally, transition elements are used as catalysts, they form coloured ions, show paramagnetism and exhibit variable oxidation states.
Zn, Cd and Hg do not show most of the properties of transition elements because of electronic configuration: (n-1) d¹⁰ns².

The two rows of elements (Lanthanoid and Actinoid) at the bottom of the periodic table are known as f-block elements.
They are also known as inner transition elements and are all metals.
Actinoid elements are radioactive in nature.