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…
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…
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…
Sir Isaac Newton was born in 1643 and died in 1727. He was a physicist, mathematician, astronomer, biologist and chemist. Newton developed three laws of motion, which described how things…
Magnets are attracted to some metals, and can attract and repel each other. The earth has a magnetic field, and so magnets can be used to find directions. Magnets and…
Friction is the force that acts between two moving surfaces and tries to stop them moving. Friction can be between two solids, a solid and a liquid, or a solid…
Density describes how much something weighs relating to its size. For example, a cubic centimetre of cork weighs less (is less dense) than a cubic centimetre of lead (which is…
Atoms (the tiny building blocks that make everything) contain protons, which have a positive charge, and electrons, which have a negative charge. Some electrons are fixed onto the atoms quite…
Heat travels in three different ways – conduction (heat travelling through a solid), convection (heat travelling through liquids and gases) and radiation (heat travelling through empty spaces). Detecting Fake Silver:…
