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Chapter-by-chapter notes written straight from the curriculum. Read free, then practise the same chapter with an AI-generated quiz.
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Learn how an endocrine gland differs from an exocrine one, where the pituitary, thyroid, adrenal, pancreas and gonads lie, which hormone each secretes and what it does, and which disorder follows from too little or too much.
Read articleLearn to build a food chain and name its trophic levels, see why a food web is more resilient than a chain, calculate how energy shrinks at each level, and understand why forests are called a lifeline.
Read articleLearn the difference between a habitat, a population, a community and an ecosystem, sort the components into biotic and abiotic, tell natural ecosystems from artificial ones, and place any organism as producer, consumer or decomposer.
Read articleLearn where fertilisation happens and what the zygote does next, how implantation works and what the placenta exchanges, the stages from zygote to foetus with the gestation period, and how the menstrual cycle relates to ovulation.
Read articleLearn why humans reproduce only sexually, label the male and female reproductive systems and state what each part does, and compare the sperm and the ovum in structure, size and number.
Read articleLearn the parts of a flower and what each does, tell self-pollination from cross-pollination and identify the pollinating agent from the flower itself, follow the pollen tube to the ovule, and see how seeds get away from the parent.
Read articleLearn how sexual and asexual reproduction differ in plants, identify natural vegetative propagation by roots, stems and leaves, understand cutting, layering and grafting, and weigh these against growing from seed.
Read articleLearn the four forces that raise sap to the top of a tree, how to demonstrate and measure transpiration with a bell jar and a potometer, what speeds transpiration up, and how it differs from guttation.
Read articleLearn how diffusion differs from osmosis, how root hairs take in water without any pump, what xylem and phloem are built from, how the two differ in direction and cargo, and how root pressure is demonstrated.
Read articleLearn to prepare carbon dioxide in the laboratory, why lime water turns milky and then clears again, why carbon monoxide is so dangerous despite having no smell, and how the greenhouse effect works.
Read articleLearn the amorphous forms of carbon and what each is used for, why heating coal without air is so much more valuable than burning it, and how wood, animal and sugar charcoal are prepared and what makes each special.
Read articleLearn where carbon occurs free and combined, what allotropy means, how the structures of diamond and graphite explain their opposite properties, and how fullerene differs from both.
Read articleLearn to identify hard water by the lather test, name the salts that cause it, tell temporary hardness from permanent, remove each by the right method with balanced equations, and weigh the advantages against the drawbacks.
Read articleLearn what water of crystallisation is and how to spot it in a formula, calculate what fraction of a crystal is really water, see the colour changes when hydrated salts are heated, and sort substances into efflorescent, deliquescent and hygroscopic.
Read articleLearn why water dissolves so much, how to tell a saturated solution from an unsaturated or supersaturated one, how to calculate solubility per hundred grams of water, and why hot water dissolves more sugar but less gas.
Read articleLearn how Earth's water is distributed and why so little of it is usable, trace the four stages of the water cycle including transpiration, list the physical properties of pure water, and see why water is densest at four degrees.
Read articleLearn the physical properties of hydrogen, how it burns and combines with metals and non-metals, how it strips oxygen out of heated metal oxides, and the test and uses that follow from all of it.
Read articleLearn where hydrogen occurs free and combined, why it resembles two different groups at once, how it is prepared in the laboratory from zinc and dilute acid, how metals behave with water, steam and acids, and how it is made industrially.
Read articleLearn to recognise combination reactions, sort decomposition into thermal, electrolytic and photochemical, use the reactivity series to predict whether a displacement will happen at all, and write double displacement equations.
Read articleLearn the observable signs that a chemical reaction has taken place, the seven conditions a reaction may need before it will start, and how to tell an exothermic reaction from an endothermic one.
Read articleLearn to turn a word equation into a skeletal one, balance it by trial and check it against the law of conservation of mass, add state symbols and conditions, and see exactly what an equation cannot tell you.
Read articleLearn the valencies of the common acidic and basic radicals, build any formula from them with the criss-cross method, work a valency backwards out of a given formula, and calculate molecular mass step by step.
Read articleLearn to read valency straight off a configuration, predict whether an atom will lose, gain or share electrons, write the symbol and charge of the ion it forms, and identify isotopes from atomic and mass numbers.
Read articleLearn to find protons, neutrons and electrons from atomic number and mass number, apply the two-n-squared rule and the Bohr-Bury scheme to write electronic configurations up to atomic number twenty, and identify valence electrons.
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