How do diffusion rates vary in different states of matter?

Diffusion rates are fastest in gases, slower in liquids, and slowest in solids due to particle mobility.

Diffusion is the process by which particles spread out from an area of high concentration to an area of low concentration. This process is influenced by the state of matter, with gases having the highest diffusion rates, followed by liquids, and then solids.

In gases, particles are far apart and move rapidly in all directions. This high speed and freedom of movement allow gas particles to mix quickly and thoroughly, resulting in high diffusion rates. For example, if you open a bottle of perfume in a room, the scent will soon spread throughout the space. This is because the perfume particles, which are in a gaseous state, are diffusing rapidly.

In liquids, particles are closer together and move slower than in gases. They can still move around and mix with each other, but the process is slower. This is why, for instance, when you drop a cube of sugar into a cup of tea, it takes a while for the sugar to dissolve and spread evenly throughout the tea.

In solids, particles are tightly packed and can only vibrate in place, so diffusion is very slow. For example, if you place a crystal of potassium permanganate on a piece of gelatine, it will take a long time for the purple colour to spread throughout the gelatine. This is because the particles in the solid state have very limited movement, slowing down the diffusion process.

Temperature also affects diffusion rates. Higher temperatures increase the energy of the particles, causing them to move faster and thus increasing the rate of diffusion. This is why food colouring will spread faster in hot water than in cold.

In summary, the state of matter significantly impacts diffusion rates due to the differences in particle mobility. Gases have the highest diffusion rates, followed by liquids, and then solids.