An example of expansion diffusion

when u walk into a room and someone is baking cookies-the smell diffuses in the air.

when u run into a skunk-the smell diffuses in the air.

when sugar dissolves in a glass when not stirring.

any form of heat like the sun, a candle, or a light bulb is diffusion.

NOTE: DIFFUSION IS WHEN SOMETHING GOES FROM HIGH CONCENTRATION TO LOW CONCENTRATION.