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Chapter 11

Chemical Changes

Eight lessons following your textbook section by section, each with something you can drag, mix, heat or break. Then a one-page map of the whole chapter and twenty interactive questions.

How this is organised

The lessons follow the four questions your textbook chapter is built around. Work through them in order the first time — each one leans on the one before.

This is scoped for G3, so everything here is examinable — including the acid-with-metals and acid-with-carbonates reactions and the electrolysis work, which the textbook marks as optional only for G2. Treat all of it as core.

A few boxes are marked Extension. Those genuinely go beyond the syllabus — balanced chemical equations, redox, atom economy. Read them if you want to see where the topic leads next, but they will not be examined.

11.1 · How do we identify a chemical change?

Lesson 1

Identifying a chemical change

Physical vs chemical, the two groups of chemical change, reactants and products.

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Lesson 2

Word equations and atoms

Writing word equations, counting atoms, and why mass is always conserved.

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11.2 · What are the different types of chemical change?

Lesson 3

Combustion, decomposition, oxidation

Three of the four types — with a live thermal decomposition and the rusting investigation.

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Lesson 4

Acids, alkalis and indicators

The pH scale, litmus, Universal Indicator and natural indicators — ten substances to test.

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Lesson 5

Reactions of acids

Neutralisation, acids with metals and carbonates, naming the salt, and the four gas tests.

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11.3 · How do chemical changes occur?

Lesson 6

How chemical changes occur

The five triggers: mixing, heating, light, oxygen and an electric current.

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Lesson 7

Electrolysis and photosynthesis

Splitting water and salt, electroplating an object, and photosynthesis as respiration reversed.

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11.4 · How does this help us in daily life?

Lesson 8

Beneficial and harmful

Cooking, respiration, decay, preventing rust, air pollutants, and ocean acidification.

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Revision

The whole chapter on one page

The concept map from the end of your chapter, plus every word equation and gas test in one place.

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Practice

20 interactive questions

Multiple choice, equation building, sorting and structured questions — marked as you go.

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Challenging · Lvl 2

Challenging Qns Lvl 2

Twenty harder questions with the options set deliberately close together — only correct reasoning separates them.

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