Which state of matter shows the highest rate of diffusion?

Gas

The correct answer is option 3. Gas.

Gas shows the highest rate of diffusion among the given options. Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. In gases, particles are typically more spaced out, and they have higher kinetic energy, allowing them to move and mix rapidly. The high mobility of gas particles enables faster diffusion compared to liquids and solids, where particles are more closely packed and have lower mobility.