Chemistry, 11–13 years — 20 topics · MyLeoNes™ Kuks
20 chemistry topics written for 11–13 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 · 11–13 years
Particles of matter
Matter may look still and continuous, but it is made of tiny particles that are always moving. This model helps explain solids, liquids and gases.
Elements and compounds
An element contains one kind of atom, while a compound joins different atoms in a fixed pattern. Knowing the difference helps you read formulas and predict what a substance is made of.
Mixtures and separation
A mixture contains substances together without turning them into one new substance. Because the parts keep their own properties, methods such as filtering, sieving and evaporation can separate them.
Chemical reactions
In a chemical reaction, particles rearrange and form new substances. Signs such as a new gas, colour change or heat can give clues, while the atoms themselves are conserved.
Reading the periodic table
The periodic table is a map of the elements. Its position gives clues about what an element is like and how it may behave.
Conservation of mass
In a chemical change, matter is rearranged rather than created or destroyed. The total mass stays the same when nothing can escape.
Acids, bases and pH
The pH scale compares how acidic or alkaline a solution is. Indicators make this invisible difference visible through colour.
Energy in chemical reactions
Chemical reactions can move energy between substances and their surroundings. Some warm things up, while others need energy from outside to happen.
Chemical bonds
Atoms join in particular ways, and those joins explain why substances have different properties.
Solubility and concentration
A substance can spread through a liquid, but only up to a limit. Concentration tells how much solute is present in a given amount of solution.
Reaction rate
Chemical reactions do not all happen at the same speed. Temperature, concentration, surface area and catalysts can change how often successful collisions occur.
Oxidation
Oxidation is a chemical change in which a substance combines with oxygen or loses electrons. It can be rapid, like burning, or slow, like rusting.
Chemical formulae
A chemical formula is a compact recipe showing which elements are present and how many atoms of each are joined in a substance.
Chemical equations
A chemical equation is a compact way to show which substances react and which new substances form.
Electrolysis
Electrolysis uses electricity to split a compound into simpler substances, showing that electrical energy can drive a chemical change.
Catalysts
How a substance can make a reaction faster without being used up.
Polymers
A polymer is a very large molecule made from many smaller repeating units, giving materials such as plastics and fibres their useful properties.
Neutralisation
What happens when an acid and a base reduce each other’s effects.
Crystallisation
How a dissolved substance can form a solid with a regular crystal shape.
Alloys
How mixing metals, or a metal with a small amount of another element, can improve its properties.
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