The periodic table is a tabular arrangement of the chemical - TopicsExpress

The periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic numbers, electron configurations, and recurring chemical properties. Elements are presented in order of increasing atomic number (number of protons). The standard form of the table comprises an 18-column-by-7-row main grid of elements, with a double row of elements below. The table can also be deconstructed into four rectangular blocks: the s-block to the left, the p-block to the right, the d-block in the middle, and the f-block below that. en.wikipedia.org/wiki/Periodic_table