Structure of the modern periodic table:
i. The modem periodic table also known as the Tong form of periodic table’ has number of boxes formed by the intersection of horizontal rows and vertical columns.
ii. The horizontal rows are called periods and the vertical columns are called groups.
iii. There are seven periods numbered from 1 to 7 and eighteen groups numbered from 1 to 18.
iv. There are total 118 boxes in the modem periodic table which are filled with 118 elements discovered till now including manmade elements.
v. The modem periodic table is divided into four blocks i.e., s-block, p-block, d-block and f-block.
- Two groups on the extreme left of the modem periodic table form the s-block.
- Six groups on the extreme right constitute the p-block.
- Ten groups in the centre form the d-block
- Two series at the bottom of the modem periodic table constitute the f-block. It contains fourteen elements in each series.
