Understanding the Periodic Table: A Complete Guide

The periodic table organizes all known chemical elements by atomic number and electron configuration. Dmitri Mendeleev created the first widely recognized version in 1869. Today it contains 118 confirmed elements arranged in 18 groups and 7 periods, revealing patterns in chemical behavior that predict properties of undiscovered elements. Understanding periodic trends like electronegativity, ionization energy, and atomic radius is fundamental to chemistry.

The table is divided into metals, nonmetals, and metalloids with distinct chemical properties..