Chemistry, 14–17 years — 20 topics · MyLeoNes™ Kuks
20 chemistry topics written for 14–17 years — not a older text simplified. In teaching order, each a deck of five cards: the idea, why it exists, a worked example, the common trap and where you meet it.
Chemistry · 14–17 years
Atoms, elements and compounds
Matter is built from atoms. Understanding the difference between elements, molecules and compounds gives chemistry a map for describing substances.
Conservation in chemical equations
A reaction rearranges atoms rather than making them vanish. Balanced equations show the same number of each kind of atom before and after the change.
Chemical bonding
Atoms join because their electrons can settle into more stable arrangements. Ionic and covalent bonding explain why substances have different structures and properties.
Acids, bases and pH
The pH scale describes how acidic or basic an aqueous solution is. It turns a chemical property into a number that can be tested, compared and used safely.
Moles and molar mass
The mole is chemistry’s way to count enormous numbers of particles by weighing them.
Concentration of solutions
Concentration describes how much dissolved substance is packed into a given volume of solution.
Energy changes in chemical reactions
Chemical reactions can transfer energy to the surroundings or take energy from them.
Reaction rates
Reaction rate describes how quickly reactants are changed into products.
Patterns in the periodic table
The position of an element gives clues about how its atoms behave. Reading these patterns lets you make sensible predictions before carrying out an experiment.
Oxidation and reduction
Many reactions involve electrons moving from one substance to another. Tracking that movement explains rust, batteries and why two reacting substances can change in opposite ways.
Dynamic equilibrium
Some reactions can go forwards and backwards. At equilibrium, both directions continue, but at equal rates, so the amounts stay steady unless conditions change.
Electrolysis
Electrolysis uses electrical energy to force a chemical change that would not happen readily on its own. It is a practical way to split compounds or coat objects with metal.
Hydrocarbons and carbon chains
Carbon can join to itself in chains and rings, making an enormous family of substances.
Functional groups
Small patterns of atoms give organic molecules their characteristic reactions and properties.
Polymers
Many small molecules can join into long chains whose properties make materials such as plastic, rubber and nylon.
Chromatography
Chromatography separates a mixture so its substances can be seen and identified.
Empirical and molecular formulae
How measurements reveal the simplest ratio of atoms in a substance, and how that ratio can be expanded to its real molecular formula.
Reacting quantities
Using a balanced equation as a recipe for converting the amount of one chemical into the amount of another.
The limiting reactant
Why a reaction stops when one reactant runs out, even if other reactants are still left.
Titration
Finding the concentration of an unknown solution by adding a solution of known concentration until the reaction is exactly complete.
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