This chapter covers the basic concepts of atoms, their structure, and chemical bonding as per the Class 9 ICSE Chemistry syllabus. Students learn about the composition of atoms, subatomic particles, electronic configuration, and how atoms combine to form compounds. The chapter builds a foundation for understanding chemical properties and reactions.Key Topics:• Structure of an atom• Protons, neutrons, and electrons• Electronic configuration• Valency• Chemical bonding• Formation of compounds and molecules