7. Classification of Elements-The Periodic Table

To study a large number of elements easily, scientists arranged them in a systematic way called the Periodic Table. This lesson explains how elements are classified based on their atomic number and similar chemical properties. Elements placed in the same group (vertical column) show similar characteristics, while periods (horizontal rows) represent the gradual change in properties across the table.

The chapter focuses on the Modern Periodic Law, which states that the properties of elements are periodic functions of their atomic numbers. Students learn about different groups such as alkali metals, alkaline earth metals, halogens, and noble gases, and understand trends like atomic size, valency, and reactivity. This classification helps scientists predict the properties of elements and understand their behavior in chemical reactions.