Concise Selina Solutions for Class 10 Chemistry Chapter 1 Periodic Table, Periodic Properties and Variations of Properties

The periodic table is an arrangement of chemical elements in the order of their atomic number, electron configurations and recurring chemical properties in a tabular form. The modern periodic table has eighteen vertical columns called groups and seven horizontal rows called periods. Elements are arranged in the order of increasing atomic numbers and show the trends in their properties. A table in which the chemical elements are arranged in order of increasing atomic number. Elements with similar properties are arranged in the same column (called a group), and elements with the same number of electron shells are arranged in the same row (called a period). The periodic variation in electron configurations as one moves sequentially through the Periodic Table from H to ever heavier elements produces a periodic variation in a variety of properties.