CBSE Class 9 Science – Structure of the Atom

Chapter Overview

The structure of the atom explains the fundamental building blocks of matter. This chapter covers various atomic models, subatomic particles, electronic configuration, and concepts like valency and isotopes. Understanding atomic structure is essential for chemistry and physics applications.

Important Keywords

• Atom: The smallest unit of matter retaining chemical properties.
• Electron: Negatively charged subatomic particle.
• Proton: Positively charged subatomic particle found in the nucleus.
• Neutron: Neutral subatomic particle in the nucleus.
• Isotopes: Atoms of the same element with different neutron numbers.
• Atomic Number (Z): Number of protons in an atom.
• Mass Number (A): Sum of protons and neutrons.