Question

Why do solids not diffuse into one another?

Answer 1

solids cannot diffuse each other because they are tightly packed and they are rigid and doesnt have fluidity.

Answer 2

Solid particles are closely and tightly packed around each other that they cannot move to diffuse into one another.

Gas particles are very far away from each other, vibrate, and move with high speeds that gases can easily diffuse into each other.

Similarly, liquid molecules can diffuse into each other, not as efficiently as gases but the particles are arranged in a manner with attractive forces that they still can move, vibrate, and slide around each other that a molecule from another liquid can find a way into the lattice (arrangement) of the first one to diffuse.

While, solid particles are arranged in a crystal lattice (arrangement) with strong attractive forces which only allow vibration of particles not movement which stop solids from diffusing into each other.