Class 9 CBSE Science Notes
Chapters 1, 2 & 3
Chapter 1: Matter in Our Surroundings
Matter: Anything that has mass and occupies space.
State Shape Volume Movement
Solid Fixed Fixed Very Less
Liquid No fixed shape Fixed Moderate
Gas No fixed shape No fixed volume Very Fast
Change of State:
Melting: Solid to Liquid
Freezing: Liquid to Solid
Vaporisation: Liquid to Gas
Condensation: Gas to Liquid
Sublimation: Solid to Gas
Chapter 2: Is Matter Around Us Pure
Pure Substance: Made of only one type of particles.
Examples: Gold, Oxygen, Distilled Water
Mixture: Two or more substances mixed together.
Homogeneous: Salt Water
Heterogeneous: Sand + Water
Separation Methods:
Filtration, Evaporation, Distillation
Chapter 3: Atoms and Molecules
Atom: Smallest unit of matter.
Molecule: Group of atoms.
Law of Conservation of Mass:
Mass is neither created nor destroyed.
Law of Constant Proportion:
Elements combine in fixed ratio.
Chapters 1, 2 & 3
Chapter 1: Matter in Our Surroundings
Matter: Anything that has mass and occupies space.
State Shape Volume Movement
Solid Fixed Fixed Very Less
Liquid No fixed shape Fixed Moderate
Gas No fixed shape No fixed volume Very Fast
Change of State:
Melting: Solid to Liquid
Freezing: Liquid to Solid
Vaporisation: Liquid to Gas
Condensation: Gas to Liquid
Sublimation: Solid to Gas
Chapter 2: Is Matter Around Us Pure
Pure Substance: Made of only one type of particles.
Examples: Gold, Oxygen, Distilled Water
Mixture: Two or more substances mixed together.
Homogeneous: Salt Water
Heterogeneous: Sand + Water
Separation Methods:
Filtration, Evaporation, Distillation
Chapter 3: Atoms and Molecules
Atom: Smallest unit of matter.
Molecule: Group of atoms.
Law of Conservation of Mass:
Mass is neither created nor destroyed.
Law of Constant Proportion:
Elements combine in fixed ratio.
