627 articles
All articles — Page 17
Every article in the chemistry library, newest first.
Teaching Electron Configuration Without the Confusion
A teacher's guide to electron configuration: a three-lesson sequence from shells to orbitals, the misconceptions students bring, hands-on activities, how to handle 4s and 3d, and a bank of check questions.
Teaching Isotopes and Relative Atomic Mass
A teacher's guide to isotopes and relative atomic mass: a two-lesson plan, the 'bag of sweets' weighted-average activity, mass spectra, common student errors and a graded question set with answers.
Teaching Lab Safety Effectively
A guide for chemistry teachers on teaching safety so it sticks: explaining the reasons behind rules, modelling behaviour, hazard-spotting activities, student-written risk assessments, drills, real case studies, dealing with incidents, and building a positive safety culture from the first lesson.
Running Safe, Successful Chemistry Practicals
A practical guide for chemistry teachers on planning and running lab lessons: trialling experiments, technician communication, risk assessment, clear routines, pre-lab questions, managing the room, keeping students thinking rather than just following steps, and effective follow-up.
Teaching Spectroscopy Interpretation
Strategies for teaching students to interpret IR, mass and NMR spectra: sequencing the techniques, a consistent problem-solving routine, building pattern recognition, using real spectra and databases, card-sort and jigsaw activities, tackling misconceptions, and assessing reasoning rather than recall.
Teaching Titration Technique
A teacher's guide to titration: a lesson sequence from equipment skills to full titrations, common student errors and how to catch them, assessing practical skills, calculations scaffolding and differentiated tasks.
Thin-Layer Chromatography (TLC)
How thin-layer chromatography works and how to do it: preparing and spotting plates, choosing a solvent, visualising colourless spots with UV and stains, calculating Rf, and using TLC to check purity and follow reactions.
Thomson's Plum Pudding Model and the Discovery of the Electron
The story of J.J. Thomson at the Cavendish Laboratory: the cathode ray mystery, the 1897 experiments that revealed the electron and its charge-to-mass ratio, the 1904 plum pudding model of the atom, why it made sense at the time, how Rutherford's experiment overturned it, and Thomson's lasting legacy.
Titration Calculations Step by Step
A reliable method for every titration calculation: 1:1 and 2:1 ratios, diluted samples, finding a molar mass, percentage purity and water of crystallisation, with six fully worked examples.
Titration Curves: Strong and Weak Combinations Explained
How pH changes during a titration for strong/strong, weak/strong, strong/weak and weak/weak pairs, with calculated key points, the buffer region, half-equivalence and indicator choice.
Common Titration Errors and How to Avoid Them
Fifteen common titration mistakes, from unrinsed burettes to overshooting the end point, with what each does to your titre and calculated concentration, and practical fixes for more accurate results.
Titration Practice Problems with Worked Answers
20 titration practice problems from basic 1:1 calculations to dilutions, back titrations, diprotic acids, percentage purity and water of crystallisation, each with a full step-by-step solution.
TLC vs Paper Chromatography
A side-by-side comparison of thin-layer and paper chromatography: stationary phases, how separation works, speed, resolution, sensitivity, visualising colourless spots, cost, typical uses in schools and research labs, and how to choose between them.
Transition Metal Electron Configurations: 4s, 3d and Ions
Worked configurations for every first-row transition metal from scandium to zinc, with the chromium and copper exceptions explained, how to write their common ions, why 3d and 4s energies cross, how configurations explain variable oxidation states, colour and magnetism, and second- and third-row surprises.
Measurement Uncertainty Practice Problems
Sixteen worked problems on measurement uncertainty: reading uncertainties of balances, burettes and pipettes, percentage uncertainty, combining uncertainties for sums, differences, products and quotients, titration and enthalpy examples, and comparing results with literature values.
Universal Indicator and the pH Colour Chart
How universal indicator shows the whole pH scale in one set of colours, what's in it, how to read the colour chart, how accurate it is, and when to use paper, solution or a pH meter instead.
How to Count Unpaired Electrons in Atoms and Ions
A step-by-step method for counting unpaired electrons: from the electron configuration to the partly filled subshell, quick rules for p, d and f subshells, a lookup table for d¹ to d¹⁰, worked examples for main-group atoms, transition metal ions and lanthanides, and practice questions with answers.
Weighing Accurately with an Electronic Balance
How to weigh solids and liquids accurately on top-pan and analytical balances: taring, weighing by difference, avoiding draughts and static, hygroscopic substances, weighing to constant mass and calculating uncertainty.
UV–Visible Spectroscopy
How UV–visible spectroscopy works: electronic transitions, chromophores and conjugation, why things are coloured, reading an absorption spectrum and λmax, the spectrophotometer, and uses in analysis and biology.
How Valence Electrons Determine Chemical Reactivity
Why is caesium explosive in water while neon ignores everything? A beginner's guide to how valence electrons, ionization energy and electron affinity decide how reactive an element is, with trends across the periodic table.
Finding the Acetic Acid Content of Vinegar
A classic titration practical: dilute vinegar accurately, titrate with standardised sodium hydroxide using phenolphthalein, and calculate its ethanoic acid concentration and percentage, with sample data and evaluation.
Vitamin C (Ascorbic Acid): Chemistry and Function
A chemical profile of vitamin C: structure and formula, why it's an acid, its antioxidant redox chemistry, its role in collagen and iron absorption, scurvy, industrial production, stability in food, and how to measure it by titration.
Vitamin D: The Sunshine Vitamin's Chemistry
How skin makes vitamin D with ultraviolet light: the photochemical ring-opening of 7-dehydrocholesterol, conversion to calcidiol and calcitriol, how the hormone controls calcium, D2 vs D3, food sources, deficiency, rickets and why latitude matters.
Vitamins: Fat-Soluble vs Water-Soluble
What vitamins are and why we need them, the chemistry behind water-soluble (B group and C) and fat-soluble (A, D, E, K) vitamins, how polarity decides storage, toxicity and cooking losses, the jobs each vitamin does, and deficiency diseases.
Volumetric Analysis: Titrations of Every Kind
An overview of volumetric analysis: acid–base, redox, complexometric and precipitation titrations, direct and back titrations, primary standards and standardisation, with an example of each type and how to choose between them.
Glassware Tolerances and Uncertainty
What the markings on volumetric glassware mean: Class A and Class B tolerances, TD and TC, calibration temperature, typical tolerance values for pipettes, burettes and flasks, and how to use them in uncertainty calculations.
Disposing of Chemical Waste Responsibly
How school and university labs handle chemical waste: why most chemicals can't go down the sink, waste categories and separate containers, neutralising dilute acids and alkalis, heavy metals, halogenated solvents, sharps and broken glass, labelling, and reducing waste in the first place.
How Drinking Water Is Tested
What water labs measure and how: microbes, chlorine, pH, hardness, nitrate, lead and other metals, fluoride and emerging contaminants, the instruments behind each test, what home test kits can and can't tell you, and how to read a water quality report.
Wave-Particle Duality: Are Electrons Waves or Particles?
An intermediate guide to wave-particle duality: evidence that light behaves as a wave and as particles, de Broglie's idea that matter has a wavelength, electron diffraction, the double-slit experiment with single electrons, why duality explains quantised energy levels, and what it means for chemistry.
Wavelength, Frequency and Photon Energy Calculations
Worked examples connecting wavelength, frequency and photon energy with c = fλ and E = hf: converting nm, pm, MHz and eV, energy per mole of photons, identifying spectral regions, comparing photon energy with bond energies, number of photons from a laser, and common unit mistakes.