Periodic table has been divided into four blocks, which blocks contain highest elements:

Explanation

Elements in the periodic table can also be classified into four blocks.This classification is based upon the valence orbital of the element involved in chemical bonding. According to this classification, elements of IA and IIA subgroups are called s-block elements because their valence electrons are available in s orbital.The elements of IIIA to VlllA subgroups (except He) areknown as p-block elements as their valence electrons are present in p orbital.Similarly in transition elements, electrons in d-orbital are responsible for their valency hence they are called d-block elements. For Lanthanides and Actinides valence electrons are present in f- orbital hence these elements are called f-block elements. This classification is quite useful in understanding the chemistry of elements and predicting their properties especially the concept of valency or oxidation state.