Structure of the Atom (CBSE Class 9 Science)
📘 Chapter 4: Structure of the Atom – (CBSE Class 9 Science) 🔹 I. Introduction Atoms were once thought to be indivisible, but discovery of subatomic particles — electrons, protons,…
Atoms and Molecules (CBSE Class 9 Science)
Atoms and Molecules 🔹 I. Laws of Chemical Combination Law of Conservation of Mass (Lavoisier) Mass can neither be created nor destroyed in a chemical reaction. Example: In the reaction…
Is Matter Around Us Pure? (CBSE Class 9 Science)
🔹 I. What is a Pure Substance? A pure substance contains only one type of particle. It has uniform composition and fixed properties (melting point, boiling point, etc.). 🔸 Examples: Pure Substance: Distilled water, pure gold, oxygen Impure Substance…
Matter in Our Surroundings (CBSE Class 9)
📘 Chapter 1: Matter in Our Surroundings – Full Explanation (CBSE Class 9 Science) 🔹 I. What is Matter? Matter: Anything that has mass and occupies space. Examples: Water, air, books, clothes, soil.…
Periodic Classification
Periodic Classification of Elements - Class 9 Introduction The classification of elements is essential to understand their properties and chemical behavior. The Modern Periodic Table, based on atomic number, systematically…