Keep the Curiosity Alive
Why do gases mix easily, while solids do not?
The ease of mixing depends on the interparticle spacing and the freedom of movement of particles in each state.
In gases:
— Interparticle attractions are negligible.
— Particles move freely and rapidly in all directions.
— There is maximum interparticle spacing between gas particles.
— When two gases are brought together, their particles move randomly and spontaneously intermingle (diffuse) into the available spaces of each other. This is why gases mix very easily and quickly.
In solids:
— Interparticle attractions are very strong.
— Particles are tightly packed with minimum interparticle spacing.
— Particles can only vibrate about their fixed positions; they cannot move past each other.
— Because solid particles have no freedom to move, they cannot intermingle with the particles of another solid under normal conditions. Hence, solids do not mix easily.
Answer: Gas particles have negligible interparticle attraction, maximum spacing, and move freely in all directions, so they diffuse and mix easily. Solid particles are tightly packed with strong interparticle attractions and can only vibrate about fixed positions, so they cannot intermingle and do not mix.