Class 9 Science Notes

Nature of science, models, scientific language and mathematics, predictions, theories and laws, and interdisciplinary science.

Studying cells with microscopes, cell structure, organelles working together, cell growth and division (mitosis, meiosis) and cell theory.

Plant tissues for growth and support, animal tissues (epithelial, connective, muscular, nervous), the musculoskeletal system and joints.

Position, distance and displacement, average speed and velocity, acceleration, motion graphs, kinematic equations and motion in a plane.

Types of mixtures, solutions and concentration, suspensions and colloids (Tyndall effect), crystallisation, distillation, centrifugation, chromatography and separating immiscible liquids.

Balanced and unbalanced forces, friction, Newton’s three laws of motion, inertia, momentum and forces on a system of objects.

Work done by a constant force, the work–energy theorem, forms of energy, mechanical energy and its conservation, power and simple machines.

Roots of atomic theory, Thomson, Rutherford and Bohr models, protons, neutrons and electrons, symbols, atomic and mass number, shells and isotopes.

Laws of conservation of mass and constant proportions, Dalton’s atomic theory, how atoms combine (ions, ionic and covalent bonds), valency and chemical formulae.

Production and propagation of sound, need for a medium, longitudinal and transverse waves, wavelength, frequency, amplitude, reflection of sound, echo and uses.

Asexual and sexual reproduction in plants and animals, vegetative propagation, human reproduction and reproductive health.

India as a biodiversity hotspot, evolution of biodiversity, need for classification, classification systems over time, five kingdoms and adaptations.

Uneven heating of the Earth, latitude and solar radiation, winds and ocean currents, local winds, biogeochemical cycles and human impact on Earth’s processes.