9 KS3 chemistry project ideas for the kitchen table

Real chemical reactions are happening in most kitchens already — rusting, fizzing, dissolving, rising bread — which makes the kitchen table one of the best places to run a genuine KS3 chemistry project without any lab equipment. Below are nine ideas built entirely around household materials, each with the chemistry concept it exercises and an explicit safety line where one's needed.

1. Test homemade indicators with red cabbage

Hook: Turn red cabbage juice into a working pH indicator and test what's actually acidic or alkaline in your kitchen. What they do: Boil red cabbage to extract the juice (adult supervision for the hob), then test a range of household liquids and record the colour changes against a pH scale. Concepts: Acids, alkalis, pH, indicators. Scope: One to two weeks. Safety note: always with an adult present for the boiling step.

2. Compare rates of rusting under different conditions

Hook: Does salt water actually rust metal faster than plain water — and by how much? What they do: Set up identical iron nails or steel wool in different conditions (dry, plain water, salt water, vinegar) and photograph and rate the rusting over one to two weeks. Concepts: Oxidation reactions, reaction rate, controlled variables. Scope: Two weeks — rust takes real time to develop visibly.

3. Investigate which household liquids are acids or alkalis, and why

Hook: Beyond just testing pH, explain what actually makes lemon juice acidic and bicarbonate of soda alkaline at the particle level. What they do: Test a range of household liquids with pH strips or a homemade indicator, then research and explain the chemistry behind two or three of the results. Concepts: Acid-alkali chemistry, particle-level explanation, hydrogen ions (introduced simply). Scope: One week.

4. Grow crystals and compare cooling rates

Hook: Does cooling a saturated solution slowly really produce bigger crystals than cooling it fast? What they do: Make a saturated salt or sugar solution, split it into two batches cooled at different rates, and compare the crystal size that forms. Concepts: Solubility, saturation, crystallisation. Scope: Two to three weeks, since good crystals need slow growth time. Safety note: adult supervision for preparing the hot solution.

5. Model a chemical reaction with a fizzy-drink experiment

Hook: Use a baking-soda-and-vinegar reaction to actually measure how much gas a chemical reaction produces. What they do: React baking soda with vinegar in a sealed setup that traps the gas (e.g. inflating a balloon on a bottle), and measure how the gas volume changes with different quantities of baking soda. Concepts: Chemical reactions, gas production, reactant quantity vs product quantity. Scope: One week.

6. Compare solubility in hot vs cold water

Hook: Does sugar actually dissolve faster — or just more — in hot water than cold? What they do: Time how long it takes a fixed amount of a substance (sugar, salt) to dissolve in hot and cold water, and separately test how much can dissolve at each temperature before it stops. Concepts: Solubility, particle theory, temperature's effect on reaction/dissolving rate. Scope: One week. Safety note: adult supervision when handling hot water.

7. Run a simple electrolysis mini-project

Hook: Split water into its component gases using nothing but a battery and some wire. What they do: Set up a simple electrolysis circuit (with adult help) using a 9V battery, pencil leads or wire electrodes, and salt water, and observe the gas produced at each electrode. Concepts: Electrolysis, decomposition reactions, elements vs compounds. Scope: One to two weeks. Safety note: always with an adult present — this project involves electrical current and gas production and should never be run unsupervised.

8. Investigate what makes bread rise: yeast vs baking powder

Hook: Two completely different chemical processes both make dough rise — which one works faster, and why? What they do: Bake two small batches of dough, one raised with yeast (a biological/fermentation process) and one with baking powder (a chemical acid-base reaction), and compare rise time and final volume. Concepts: Chemical vs biological gas-producing reactions, comparing reaction mechanisms. Scope: One to two weeks. Safety note: adult supervision for oven use.

9. Compare fizzy-drink reaction rates with different concentrations

Hook: Following on from the balloon experiment above, does doubling the baking soda actually double the gas produced, or is the relationship more complicated? What they do: Run the vinegar-and-baking-soda reaction at several different baking soda quantities, measuring gas volume each time, and graph the relationship. Concepts: Reaction rate, proportional vs non-proportional relationships, graphing scientific data. Scope: One to two weeks.

For a wider set of hands-on science ideas across subjects, see science fair project ideas, and for help choosing which of these fits your child best, helping your child choose a project topic covers the filter to use.