Science (Class 9) — Free Notes (CBSE & HBSE)
Free Class 9 Science notes — Matter, Atoms and Molecules, Structure of the Atom, Cell, Tissues, Motion, Force and Laws of Motion, Gravitation, Work and Energy, Sound and Food Resources — with diagrams, solved examples, MCQs and important questions for CBSE and HBSE. Free Class 9 Science course on SikshaSarovar.
Free, chapter-wise Science notes for Class 9 on Siksha Sarovar, aligned to NCERT and both CBSE and Haryana Board (HBSE). Covers 12 chapters with explanations, worked examples and board-pattern practice questions.
Chapters covered (12)
- Matter in Our Surroundings — CBSE emphasises the particle nature of matter, change of state with energy concepts (latent heat) and quantitative reasoning, while HBSE focuses on definitions, properties of the…
- Is Matter Around Us Pure — CBSE stresses the classification of matter, distinguishing solutions/suspensions/colloids using the Tyndall effect and applying separation techniques to mixtures, while HBSE…
- Atoms and Molecules — CBSE emphasises the laws of chemical combination, mole concept numericals and writing chemical formulae using valency, while HBSE focuses on definitions, symbols, atomic and…
- Structure of the Atom — CBSE emphasises the historical evolution of atomic models (Thomson to Rutherford to Bohr) with reasoning behind each, plus numerical practice on atomic number, mass number and…
- The Fundamental Unit of Life — CBSE focuses on detailed structure-function of organelles, osmosis experiments and well-labelled diagram-based reasoning (plant vs animal cell, prokaryote vs eukaryote). HBSE…
- Tissues — CBSE emphasises classification with structure-function correlation and labelled-diagram-based reasoning for plant (meristematic/permanent) and animal tissues. HBSE focuses on…
- Motion — CBSE emphasises graphical interpretation (distance-time and velocity-time graphs), derivation of the three equations of motion, and uniform circular motion as a numerical and…
- Force and Laws of Motion — CBSE stresses the conceptual statements of Newton's three laws, the link between force and momentum (F = Δp/Δt) and numericals on conservation of momentum, including recoil and…
- Gravitation — CBSE emphasises the universal law of gravitation, deriving and using g, distinguishing mass from weight, and the full fluid sub-topic (thrust, pressure, buoyancy, Archimedes'…
- Work and Energy — CBSE emphasises the scientific definition of work, derivation of kinetic energy, and the law of conservation of energy with numerical applications; HBSE focuses on direct…
- Sound — CBSE emphasises the wave nature of sound, characteristics (pitch, loudness, timbre), v=λf derivation-style numericals, echo and SONAR; HBSE focuses on production/propagation,…
- Improvement in Food Resources — CBSE emphasises crop variety improvement, nutrient management, cropping patterns and integrated practices in animal husbandry; HBSE focuses on definitions and short-answer…
Matter in Our Surroundings: Characteristics of Particles of Matter
What is Matter?
Matter is anything that has mass and occupies space (volume). Air, water, stones, plants, animals and even smell-causing gases are all matter.
Early Indian philosophers classified matter into the Panch Tatva — air, earth, fire, sky and water. Modern science classifies matter on the basis of physical state (solid, liquid, gas) and chemical composition (elements, compounds, mixtures).
Particle Nature of Matter
Matter is made up of tiny particles. These particles are extremely small — far beyond what we can see.
When potassium permanganate (a few crystals) is dissolved in water and diluted repeatedly, the colour still persists, proving that even a tiny crystal contains a huge number of particles.
Characteristics of Particles
| Characteristic | Meaning / Evidence |
|---|---|
| Particles are very small | A crystal of KMnO4 colours thousands of litres of water |
| Particles have space between them | Sugar/salt dissolves in water without raising the level much |
| Particles are continuously moving | They possess kinetic energy; diffusion proves this |
| Particles attract each other | A force of attraction holds particles together |
Diffusion
Diffusion is the intermixing of particles of two different types of matter on their own. It is faster in gases, slower in liquids and negligible in solids.
- Rate of diffusion increases with temperature because kinetic energy of particles increases.
- Smell of incense/perfume spreading across a room is diffusion in gases.
CBSE trap: Diffusion proves BOTH that particles have space between them AND that they are in continuous motion.
Frequently asked questions
Are these Science notes free?
Yes — all Science notes on Siksha Sarovar are free to read, no account required.
Do the notes follow CBSE and HBSE?
Yes. Notes are NCERT-aligned and include both CBSE and Haryana Board (HBSE) exam guidance, important questions and MCQs.
Can I prepare for board exams here?
Yes — each chapter includes key concepts, formulas, important questions and practice MCQs for board exam revision.