Diffusion in gases and liquids
Matter and Its States · Chemistry
Study notes
A teacher opens a perfume bottle at the front of the classroom. Students at the back smell it after a minute. Explain. Step 1: Perfume liquid evaporates into vapour particles. Step 2: These particles move randomly and collide with air molecules. Step 3: Slowly they spread from high concentration (bottle) to low concentration (back of room). Step 4: This spreading without stirring is diffusion. Step 5: It is slow in air because particles keep colliding; in vacuum it would be instant.