13 chapters · Topics & Key Concepts
Chemical equations, balancing of equations, types of reactions (combination, decomposition, displacement, double displacement, redox, exothermic, endothermic), oxidation and reduction, corrosion, rancidity
A chemical reaction converts one or more substances into new substances. Chemical equations are symbolic representations; they must be balanced to obey conservation of mass. Oxidation and reduction occur simultaneously (redox). Corrosion (rusting of iron) and rancidity (spoilage of fats) are everyday redox processes.
Properties of acids and bases, neutralisation, reactions of acids and bases with metals/oxides/carbonates, pH scale, importance of pH in everyday life, salts, plaster of Paris, baking soda, washing soda, bleaching powder
Acids produce H+ ions in water; bases produce OH- ions. Strong acids and bases ionise completely; weak ones partially. The pH scale measures H+ ion concentration. Neutralisation produces salts and water. Common salts like baking soda, washing soda, plaster of Paris and bleaching powder have wide household and industrial uses.
Physical and chemical properties of metals and non-metals, reactivity series, ionic bonds, properties of ionic compounds, occurrence of metals, extraction (low/medium/high reactivity), refining, corrosion and its prevention
Metals are lustrous, malleable, ductile, sonorous and good conductors. Non-metals are generally dull, brittle and poor conductors. The reactivity series ranks metals by reactivity. Extraction of metals depends on their position in the series. Ionic compounds form by electron transfer and have high melting points, are soluble in water and conduct electricity when molten or in solution.
Tetravalency of carbon, covalent bonding, allotropes of carbon, saturated and unsaturated hydrocarbons, IUPAC nomenclature, isomerism, functional groups, combustion, oxidation, addition, substitution reactions, ethanol, ethanoic acid, soaps and detergents
Carbon forms a huge variety of compounds due to its tetravalency, catenation and ability to form multiple bonds. Alkanes are saturated hydrocarbons; alkenes and alkynes are unsaturated. Functional groups give characteristic properties to organic molecules. Soaps and detergents clean by emulsifying oils and dirt; soaps form scum in hard water while detergents do not.
Nutrition, respiration, transportation, excretion; photosynthesis in plants; human digestion; aerobic and anaerobic respiration; blood, heart, blood vessels; xylem, phloem; kidneys and nephron
Life processes are essential to maintain life: nutrition provides energy and raw materials; respiration releases energy from food; transportation distributes materials; excretion removes wastes. In plants, photosynthesis produces food using sunlight, chlorophyll, water and CO2. The four-chambered heart pumps blood. Excretion occurs through nephrons in the kidneys.
Nervous system (central and peripheral, brain, spinal cord, neurons, reflex action, reflex arc), endocrine glands and hormones (thyroid, pituitary, adrenal, pancreas, gonads), coordination in plants (tropisms, phytohormones)
Control and coordination in animals is achieved by the nervous and endocrine systems. Reflex actions are quick, involuntary responses to stimuli, mediated by the spinal cord. Hormones travel through the bloodstream to target organs and regulate growth, metabolism and reproduction. In plants, coordination is brought about by phytohormones and tropisms.
Importance of reproduction, modes of asexual reproduction (fission, budding, fragmentation, regeneration, spore formation, vegetative propagation), sexual reproduction in flowering plants, human reproduction, reproductive health (contraception, STDs)
Reproduction ensures the continuity of life. Asexual reproduction (single parent) gives clones; sexual reproduction (two parents) gives variations through combination of genes. In plants, pollination is followed by fertilisation and seed/fruit formation. In humans, fertilisation occurs in the fallopian tube. Reproductive health includes prevention of STDs and use of safe contraception.
Heredity, variations, Mendel's contributions, laws of inheritance (dominance, segregation, independent assortment), monohybrid and dihybrid cross, sex determination in humans
Heredity is the transmission of characters from parents to offspring. Mendel, the father of genetics, performed experiments on pea plants and proposed the laws of inheritance. Each trait is controlled by a pair of alleles; one is dominant, the other recessive. In humans, sex is determined by chromosomes contributed by the father.
Reflection of light, laws of reflection, spherical mirrors (concave and convex), mirror formula, magnification, ray diagrams, refraction, laws of refraction, refractive index, lens formula, magnification by lens, power of a lens, sign conventions
When light strikes a smooth surface, it follows the laws of reflection. Spherical mirrors form different types of images depending on the position of the object. Refraction occurs when light passes from one medium to another; Snell's law governs the angles. Lenses form images according to the lens formula. Power of a lens measures its ability to converge or diverge light.
Structure of the human eye, power of accommodation, defects of vision (myopia, hypermetropia, presbyopia) and their correction, refraction through prism, dispersion, scattering of light, atmospheric refraction (twinkling stars, advanced sunrise), rainbow
The human eye can adjust to see objects at different distances (accommodation). Myopia, hypermetropia and presbyopia are common defects corrected by suitable lenses. A prism disperses white light into constituent colours. Scattering of light by air molecules explains the blue sky. The sun appears red at sunrise and sunset due to preferential scattering of shorter wavelengths.
Electric current, potential difference, Ohm's law, resistance, resistivity, factors affecting resistance, combination of resistors (series and parallel), heating effect, electric power
Electric current is the flow of electric charge. Ohm's law gives the linear relation between current and potential difference at constant temperature. Resistance opposes current and depends on material, length and cross-section. In series, resistances add; in parallel, reciprocals add. Joule's heating is the basis of many electrical appliances.
Magnetic field and field lines, field due to current-carrying conductor, right-hand thumb rule, circular loop and solenoid, force on current-carrying conductor in magnetic field, Fleming's left-hand rule, electric motor, electromagnetic induction, Fleming's right-hand rule, electric generator, domestic electric circuits
Electric currents produce magnetic fields, as discovered by Oersted. A current-carrying conductor in a magnetic field experiences a force — the basis of an electric motor. Electromagnetic induction (Faraday's law) is the basis of generators. Fleming's rules give directions in motors and generators. Domestic circuits use earth, live and neutral wires; fuse and MCB ensure safety.
Ecosystem and its components, food chain, food web, trophic levels, flow of energy, biological magnification, ozone layer and its depletion, waste management (biodegradable and non-biodegradable)
An ecosystem includes living organisms and the non-living environment interacting as a unit. Energy flows through food chains with about 10% transferred between trophic levels. Biological magnification of non-biodegradable substances harms top consumers. CFCs deplete the ozone layer which protects life from harmful UV radiation. Biodegradable wastes decompose naturally; non-biodegradable wastes persist and harm the environment.
