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…
The pH scale is a scale of numbers that describes how acid or alkaline (another word for alkaline is ‘basic’) something is. A pH indicator is a liquid or paper…
Water molecules at the surface of a glass of water are more strongly attracted to each other than to water molecules in the rest of the water. This creates a…
Polymers are made of long molecules like chains that stick to each other (cross-link). Natural polymers include hair, wool and cellulose (in plants). Plastic is a synthetic polymer. ‘Silly Putty’…
Hot water has more energy than cold water. This makes the water molecules move around more. Molecules that move more take up more space, but still weigh the same, so…
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…
As air gets warm, the air molecules have more energy and move around more, taking up more space. As the warm air expands, it becomes less dense (see ‘Floating and…
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…
