A spoon of sugar disappears in a glass of water, and the water does not overflow. A smell of food spreads across a house. In this course we find what matter is made of, how its particles behave, and how this gives us the solid, the liquid and the gas.
3 lessons, about 1 h 25 min3 simulations10 problems6 practice questionsPython in every lesson
Created by StemPy LabMatter is anything that has mass and takes up space. It is made of very small particles, and there are spaces between them. A few crystals of potassium permanganate can colour a large amount of water, so the particles must be very small and very many. Sugar dissolves in water without a rise in the level, because its particles go into the spaces between the particles of water. Air can be squeezed because its particles are far apart.
The particles of matter are always moving, and so they have kinetic energy. Diffusion is the spreading of the particles of one substance into another by themselves. It is faster in gases than in liquids, and faster at a higher temperature, because heated particles move faster. There is also a force of attraction between the particles of matter, which keeps them together. It is strong in an iron nail and weaker in chalk or water, and its strength is different in different kinds of matter.
Matter is a solid, a liquid or a gas. A solid has a fixed shape and volume, a liquid has a fixed volume but no fixed shape, and a gas has neither. The difference comes from how close the particles are and how strongly they attract each other.
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