A block of ice, a puddle and a cloud of steam are all the same water molecules. What changes between them is not the particles themselves but how tightly they are packed and how freely they move.
In a solid, particles are packed closely in a regular pattern and only vibrate. In a liquid they are still close but can slide past one another. In a gas they are far apart and move quickly in all directions. The particles are the same; only their arrangement and motion change.
A solid has a fixed shape and volume, a liquid has a fixed volume but takes the shape of its container, and a gas fills its container completely and is easily compressed.
The particles do not change when a substance melts or boils; only their spacing and motion change.
Switch between solid, liquid and gas and watch how the particle arrangement and motion change.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
In which state are the particles held in a fixed, regular arrangement?
The particles in a gas...
Which state can be compressed easily?
A liquid takes the shape of its container but keeps a fixed...
Each property of a state follows directly from how its particles are arranged and how they move.
The particles themselves do not change between states. When ice melts or water boils, each molecule is identical before and after; what changes is how close together the particles are, how ordered they are, and how fast they move.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
A substance has a fixed volume but takes the shape of its container. It is a...
When a solid is heated until it melts, its particles...
Compared with the same substance as a liquid, the gas has particles that are...
That completes the first skill in the particle model. Keep the chain going.