Notes
Reading material from teachers and learners: theory, worked examples and questions that make you think. Some notes are made with AI, and they always say so.
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Transistors and Logic GatesHigh School (11–12)
Transistors and Logic Gates: Quick Revision
A brief note on Transistors and Logic Gates: the junction transistor and its characteristics, the amplifier and the switch, and the logic gates with their truth tables, with a worked example, practice and questions to check yourself.
Groups 17 and 18: Halogens and Noble GasesHigh School (11–12)
Halogens and Noble Gases: Quick Revision
A brief note on the halogens and the noble gases: trends in group 17, chlorine, hydrogen chloride, interhalogen compounds, the oxoacids of chlorine, and the noble gases with the fluorides and oxides of xenon. With a worked example, practice, a program and questions to check yourself.
StatisticsHigh School (11–12)
Correlation and Regression: Quick Revision
A brief note on correlation and regression: the scatter plot, the correlation coefficient, the two regression lines, prediction and the usual traps. With a worked example, practice, a program and questions to check yourself.
Organisms and PopulationsHigh School (11–12)
Interactions Between Species: Quick Revision
A brief note on Interactions Between Species: the signs of predation, competition, parasitism, commensalism, amensalism and mutualism, with their standard examples and the usual slips, and questions to check yourself.
Trigonometry and Waves by ComputerHigh School (11–12)
Waves by Computer: Adding and Fitting: Quick Revision
A brief note on Waves by Computer: the travelling wave in numpy, adding waves for beats and standing waves, harmonics of a string, the FFT, sampling and aliasing, and fitting a sine with curve_fit. With practice, a program and questions.
Averages: Mean, Median and ModeMiddle Stage (6–8)
A Data Project from Question to Report
The Weather Project: the six steps of a data project, showing a month of weather, its centre, spread and chances, linked days, and an honest report with a limit. With a worked example, practice, a program and questions.
Semiconductors and DiodesHigh School (11–12)
Rectifiers, Zener Diodes and Light Devices: Quick Revision
A brief note on Rectifiers, Zener Diodes and Light Devices: half-wave and full-wave rectifiers, the capacitor filter, the Zener regulator, the LED, the photodiode and the solar cell, with a worked example, practice and questions to check yourself.
Groups 15 and 16: Nitrogen and Oxygen FamiliesHigh School (11–12)
Oxygen, Ozone and Sulphur: Quick Revision
A brief note on oxygen, ozone and sulphur: the trends of group 16, the oxides, ozone and its layer, sulphur and its allotropes, sulphur dioxide, the contact process, sulphuric acid and the oxoacids of sulphur. With a worked example, practice, a program and questions to check yourself.
StatisticsHigh School (11–12)
Comparing and Combining Data: Quick Revision
A brief note on comparing and combining data: the coefficient of variation, the effect of changing every value, the combined mean and variance, quartiles, box plots and outliers. With a worked example, practice, a program and questions to check yourself.
Organisms and PopulationsHigh School (11–12)
Population Attributes and Population Growth: Quick Revision
A brief note on Population Attributes and Population Growth: births, deaths and migration, the sex ratio, the age pyramids, and the exponential and logistic curves with r and K, with the usual slips and questions to check yourself.
Trigonometry and Waves by ComputerHigh School (11–12)
Angles, the Unit Circle and Trigonometric Graphs: Quick Revision
A brief note on Angles, the Unit Circle and Trigonometric Graphs: degrees and radians, the unit circle, the graphs of sine, cosine and tangent, and checking identities with numpy. With a worked example, practice, a program and questions.
Probability and ChanceMiddle Stage (6–8)
Probability: Quick Revision
A brief note on Chance: probability by counting, the chance that something does not happen, relative frequency and the long run, two events together, at least one, and taking without putting back. With a worked example, practice, a program and questions.
Semiconductors and DiodesHigh School (11–12)
Energy Bands, Doping and the p-n Junction: Quick Revision
A brief note on Energy Bands, Doping and the p-n Junction: bands and gaps, electrons and holes, n-type and p-type, the depletion layer, bias and the diode equation, with a worked example, practice and questions to check yourself.
Groups 15 and 16: Nitrogen and Oxygen FamiliesHigh School (11–12)
Nitrogen and Phosphorus: Quick Revision
A brief note on nitrogen and phosphorus: the trends of group 15, ammonia and the Haber process, the oxides of nitrogen, nitric acid, the allotropes and chlorides of phosphorus, and its oxoacids. With a worked example, practice, a program and questions to check yourself.
StatisticsHigh School (11–12)
Centre and Spread of Data: Quick Revision
A brief note on centre and spread of data: the mean, median and mode, the range, the mean deviation, the variance and the standard deviation, for lists, frequency tables and grouped data. With a worked example, practice, a program and questions to check yourself.
Organisms and PopulationsHigh School (11–12)
Organisms and Their Environment: Quick Revision
A brief note on Organisms and Their Environment: the major abiotic factors with their numbers, the four responses to a hard environment and the adaptations of plants and animals, with the usual slips and questions to check yourself.
Biology by ComputerHigh School (11–12)
Genetics by Computer: Quick Revision
A brief note on Genetics by Computer: gametes as letters, sorted genotypes, Punnett squares with loops and Counter, two genes with itertools.product and the 9:3:3:1 ratio, the test cross, and simulated crosses with random.choice. With practice, a program and questions.
Spread of DataMiddle Stage (6–8)
Range, IQR and Standard Deviation: Quick Revision
A brief note on Spread: the range, quartiles and the IQR, box plots, the variance and the standard deviation, which measure to use, and what adding or multiplying does to the spread. With a worked example, practice, a program and questions.
Nuclei and RadioactivityHigh School (11–12)
Nuclear Reactions, Fission and Fusion: Quick Revision
A brief note on Nuclear Reactions, Fission and Fusion: the Q value and the threshold, the chain reaction and the reactor, and fusion in the Sun and on Earth, with a worked example and questions to check yourself.
Groups 13 and 14: Boron and Carbon FamiliesHigh School (11–12)
The Boron Family: Quick Revision
A brief note on the boron family: trends of group 13, the odd behaviour of boron, borax, boric acid, diborane and aluminium. With a worked example, practice, a program and questions to check yourself.
Random Variables and Probability DistributionsHigh School (11–12)
Random Variables and the Binomial Distribution: Quick Revision
A brief note on random variables and the binomial distribution: the table of a distribution, the mean and the variance, the effect of , Bernoulli trials, the binomial formula and the normal approximation. With a worked example, practice, a program and questions to check yourself.
Human Health and DiseaseHigh School (11–12)
Cancer, Drugs and Alcohol Abuse: Quick Revision
A brief note on Cancer, Drugs and Alcohol Abuse: tumours, carcinogens, detection and treatment of cancer, the commonly abused drugs and tobacco, and addiction, with the usual slips and questions to check yourself.
Biology by ComputerHigh School (11–12)
Growth and Populations by Computer: Quick Revision
A brief note on Growth and Populations by Computer: exponential growth, log axes, doubling time, logistic growth stepped in code, and fitting curves with polyfit and curve_fit. With a worked example, practice, a program and questions to check yourself.
Data and SamplingMiddle Stage (6–8)
Data Tables, Kinds of Data and Fair Samples
A brief note on What Is Data?: tables of cases and variables, the four kinds of data, and how to choose a fair sample and ask a fair question. With a worked example, practice, a program and questions.
Nuclei and RadioactivityHigh School (11–12)
Radioactive Decay and Half-Life: Quick Revision
A brief note on Radioactive Decay and Half-Life: alpha, beta and gamma decay, the law of decay with half-life and mean life, and activity, decay series and dating, with a worked example and questions to check yourself.