Oil and water are described as immiscible liquids – liquids that do stay mixed together (see ‘Why Oil and Water Don’t Mix’). Even if oil and water are thoroughly shaken…
Drinks are fizzy because they have carbon dioxide in them – the gas is forced into the drink at low temperatures and dissolves. Homemade fizzy drinks can be made using…
Invisible ink, sometimes called ‘sympathetic ink’, is a way of writing secret messages. Spies have used invisible inks to pass on secret messages, as have prisoners and hostages. Invisible Messages…
Soap is made from animal fats and vegetable oils, mixed with a caustic chemical called sodium hydroxide (also known as lye). The sodium hydroxide reacts with the oil to make…
What is a summer without ice cream cones, or a slice of apple pie without a melting scoop of vanilla ice cream? Though it looks simple – cream, milk, sugar…
As light passes through transparent objects, it bends. This can create optical illusions like disappearing bowls, bending pencils and mirages. This is called refraction, and is useful in magnifying glasses…
Water exists in three states – solid ice, liquid water and gaseous steam. Solids have a fixed shape and size. Liquids can change in shape, but have a fixed size….
Heat travels through solids by conduction (see also ‘Detecting Fake Silver: Conductivity of Metal’). Insulation can keep things warm and keep things cool by reducing heat transfer through conduction. Insulation…
Sounds are created from vibrations, whether it’s a tuning fork, the reed of a musical instrument, or sound coming from someone’s voice box. The vibrations make the air molecules move…
