Waves: Making the Invisible Visible in a Bowl of Water

Waves: Making the Invisible Visible in a Bowl of Water

Waves: Making the Invisible Visible in a Bowl of WaterSarah Kennett
Published on: 09/09/2026

Watch invisible waves become visible in a bowl of water. A hands-on way to measure frequency, wavelength and wave speed for the exam.

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Density: Why the Stone Sinks and the Apple Doesn't

Density: Why the Stone Sinks and the Apple Doesn't

Density: Why the Stone Sinks and the Apple Doesn'tSarah Kennett
Published on: 02/09/2026

Drop a stone and an apple in water: one sinks, one floats. A required practical for measuring mass, volume and density of regular solids, irregular solids and liquids using kitchen scales and a measuring jug.

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Chromatography: Why a Black Felt Tip Isn't Actually Black

Chromatography: Why a Black Felt Tip Isn't Actually Black

Chromatography: Why a Black Felt Tip Isn't Actually BlackSarah Kennett
Published on: 26/08/2026

Get a black felt tip pen wet and watch it split into blues, purples and pinks. A simple filter-paper practical for testing whether a dye is pure or a mixture, plus how to read an Rf value from the result.

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Enzyme Activity and pH: What's Actually Happening When Bread Tastes Sweeter the Longer You Chew It

Enzyme Activity and pH: What's Actually Happening When Bread Tastes Sweeter the Longer You Chew It

Enzyme Activity and pH: What's Actually Happening When Bread Tastes Sweeter the Longer You Chew ItSarah Kennett
Published on: 19/08/2026

Chew bread for a minute and it starts tasting sweet - that's amylase breaking starch into sugar. Turn it into a required practical testing how pH affects enzyme activity, with an iodine colour-change timer you can do in your kitchen.

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