Blog topic
Chemistry articles
Acids and bases, why iron rusts, how the periodic table is arranged, bonding, catalysts, solubility, distillation, isotopes and polymers, plus the calculation guides on molar mass, empirical formula and percent yield. Read the calculation pieces with a pencil.
43 explainers, newest first. Each one ends with real questions from the unit that teaches it, so you can read the explanation and then check whether it stuck.
These are the readable companion to the Chemistry track, which holds 18 units and 2,059 practice questions. If you are starting the subject rather than looking something up, the study guide is the better place to begin.
How Is Steel Made? Iron, Carbon and the Furnace
Steel is iron with a little carbon and a lot of control. How ore becomes iron, how iron becomes steel, and why a fraction of a percent of carbon matters.
October 19, 20268 min readHow Is Perfume Made? Notes, Fixatives and the Chemistry of Scent
A perfume is a solution of scented molecules in alcohol, built so that light ones open and the heaviest last for hours. Where the materials come from.
October 15, 20268 min readHow Does Rubber Work? Why It Stretches, Snaps Back and Once Melted in Summer
Rubber stretches to several times its length and returns because its molecules are long tangled chains that straighten under load. What vulcanisation did.
October 14, 20268 min readHow Does Concrete Work? Cement, Water and the Chemistry of Setting
Concrete is the most used material on Earth after water, and it hardens by a reaction that grows crystals, not by drying. What cement is, and why steel goes in.
October 12, 20268 min readHow Does Bleach Work? Chlorine, Oxygen and the Chemistry of Taking Colour Away
Bleach removes colour and kills germs by oxidation, breaking the bonds that absorb light and the proteins microbes need. Why not to mix it.
October 9, 20268 min readWhy Is Glass Transparent? A Solid That Never Quite Froze
Glass lets light through because its electrons cannot absorb visible photons and its structure has no grain to scatter them. What glass is, and why sand is not.
October 7, 20268 min readWhat Are the Noble Gases? The Elements That Refuse to React
Helium, neon, argon, krypton, xenon and radon barely combine with anything. Why a full outer shell makes them inert, how they were found.
October 5, 20267 min readHow Does Soap Work? A Molecule With Two Opposite Ends
Soap lifts grease off skin and dishes because each of its molecules has a water-loving end and a fat-loving end.
October 3, 20268 min readHow Does Radiocarbon Dating Work? Counting the Clock in Dead Wood and Bone
Radiocarbon dating measures how much of a radioactive form of carbon remains in something once alive. How the clock is set, how it is read, and where it stops.
October 1, 20268 min readHow Does Fire Work? The Chemistry of Combustion
Fire is a chain reaction between fuel and oxygen that makes its own heat. Why it needs three things to start, why the flame glows, and what the colours mean.
September 29, 20268 min readHow to Calculate Empirical Formula Step by Step
Learn how to calculate empirical formula from masses or percentages by converting to moles, finding ratios, and turning them into whole-number subscripts.
August 17, 20269 min readWhat Is a Limiting Reactant? A Simple Chemistry Guide
Learn how to use a balanced equation and mole ratios to find which reactant runs out first and limits product formation.
August 17, 20269 min readHow to Calculate Percent Yield Step by Step
Learn how to calculate percent yield from actual yield and theoretical yield, use the percent yield formula correctly, and avoid common chemistry mistakes.
August 17, 20268 min readWhat Is an Endothermic Reaction? Energy Changes Explained
Learn how some reactions absorb energy from their surroundings, how energy diagrams show it, and why temperature may fall.
August 17, 20269 min readWhat Is Titration? A Simple Guide to Measuring Concentration
Learn how a solution of known concentration can be used to find an unknown concentration with careful measuring and an endpoint.
August 17, 20269 min readHow to Draw Lewis Structures Step by Step
Learn how to draw Lewis structures by counting valence electrons, arranging bonds and lone pairs, checking octets, and testing the final electron count.
August 17, 20269 min readWhat Is Electronegativity? A Simple Chemistry Guide
Learn how strongly atoms attract bonding electrons, how the periodic trend works, and why differences affect bond polarity.
August 14, 20268 min readWhat Is Oxidation and Reduction? Redox Reactions Made Simple
Learn how electrons move in redox reactions, how oxidation states help, and why the two processes always happen together.
August 14, 202610 min readWhat Is an Exothermic Reaction? Energy Changes Explained
Learn why some reactions transfer energy to their surroundings, how temperature changes, and how energy diagrams help.
August 14, 20269 min readHow to Calculate Concentration in Chemistry Step by Step
How to calculate concentration becomes simple with the right units. Learn concentration in mol per dm3, rearrange the formula, and avoid volume mistakes.
August 14, 20269 min readWhat Is a Mole in Chemistry? Counting Particles with Avogadro's Number
Learn how chemists count atoms and molecules, use Avogadro's number, and connect moles with mass in calculations.
August 14, 20269 min readWhat Is Electrolysis? Using Electricity to Drive Chemical Change
Learn how electric current drives non-spontaneous chemical reactions, what happens at electrodes, and how ions move in an electrolyte.
August 14, 202610 min readWhat Are Hydrocarbons? Carbon and Hydrogen Compounds Explained
Learn how compounds made only of carbon and hydrogen form chains and rings, and how alkanes, alkenes, and combustion differ.
August 14, 202610 min readWhat Are Valence Electrons? The Outer Electrons That Shape Reactions
Learn how outer shell electrons connect to bonding, reactivity, ions, and repeating patterns across the periodic table.
August 14, 20269 min readWhat Is Activation Energy? Why Reactions Need a Starting Push
Learn why chemical reactions need a minimum energy barrier, how temperature affects collisions, and how catalysts lower it.
August 14, 20269 min readWhat Are Ions? How Atoms Become Charged
Learn how atoms gain or lose electrons, why positive and negative ions form, and how ionic charge connects to chemical bonding.
August 14, 20269 min readHow to Balance Chemical Equations Step by Step
Learn how to balance chemical equations by changing coefficients, counting atoms on both sides, and keeping every chemical formula unchanged.
August 13, 20269 min readHow to Calculate Molar Mass Step by Step
Learn how to calculate molar mass from a chemical formula using atomic masses, subscripts, brackets, and a careful total, with clear worked examples.
August 13, 20268 min readHow Alloys Change the Properties of Metals
Alloys mix a metal with other elements to change its properties. Different atoms can make a material harder, stronger, more corrosion-resistant or better suited to a particular job.
August 8, 20269 min readHow Crystallisation Purifies a Solid
Crystallisation separates a dissolved solid from a solution by changing how much solute the solvent can hold. Careful heating, cooling and filtration can produce crystals while leaving many impurities behind.
August 8, 20269 min readHow the Reactivity Series Predicts Metal Reactions
The reactivity series ranks metals by how readily they lose electrons. It helps you predict reactions with water, acids and compounds containing other metals.
August 5, 20269 min readHow Reversible Reactions Reach Equilibrium
In a reversible reaction, products can react to form the original reactants. Dynamic equilibrium is reached when forward and reverse reactions continue at equal rates.
August 5, 20269 min readHow Chromatography Separates Mixtures
Chromatography separates dissolved substances by making them travel through a material at different speeds. Attraction to the mobile and stationary phases determines how far each component moves.
August 4, 20268 min readHow Distillation Separates Mixtures
Distillation separates substances by using differences in boiling point. A liquid is vaporised, carried away from less volatile material and condensed into a new container.
July 29, 20269 min readHow Isotopes Change an Element's Mass
Isotopes are atoms of the same element with different numbers of neutrons. They share an atomic number but differ in mass and sometimes in nuclear stability.
July 29, 20269 min readHow Polymers Form Long Molecular Chains
Polymers are large molecules built from repeating smaller units called monomers. Their chain length, branching and links help explain the wide range of properties found in plastics and natural materials.
July 29, 20269 min readHow Ionic and Covalent Bonds Hold Atoms Together
Atoms form bonds by changing or sharing their outer electrons. Ionic and covalent bonding are two different routes toward more stable arrangements.
July 26, 20269 min readHow Catalysts Speed Up Chemical Reactions
Catalysts make reactions faster by providing a route with lower activation energy. They take part in the process without being used up overall.
July 26, 20269 min readHow Solubility Controls What Dissolves
Dissolving happens when attractions between solute and solvent particles can compete with the attractions already present. Temperature, pressure and particle type all influence how much can dissolve.
July 26, 20269 min readAcids, Bases, and the pH Scale in Everyday Life
Acids and bases appear in food, cleaning, digestion, soil, and water. The pH scale helps you compare them without turning chemistry into a swamp of mysterious numbers.
July 24, 202610 min readWhy Iron Rusts and How We Slow It Down
Rust forms when iron reacts with oxygen and water. Understanding that reaction explains why paint, oil and protective metal coatings can keep iron objects useful for longer.
July 24, 20269 min readHow the Periodic Table Organises the Elements
The periodic table is more than a list of chemical symbols. Its rows and columns reveal patterns in atomic structure and help you predict how elements may behave.
July 24, 20269 min readA Beginner's Guide to Chemistry
Chemistry is the story of what everything is made of and how it changes. Start with atoms, meet a few reactions, and see the science hiding in your kitchen.
December 11, 20257 min read