Question

if gas molecules are moving so fast (around 500 m/s), why do most smells travel at significantly less than that? (if i open a container of smelly stuff at the front of the classroom it takes a few seconds to smell it - why?) draw and attach a picture to help you describe this.

Answer 1

Smells travel at a slower speed than individual gas molecules due to the random and frequent collisions that change molecules' directions, as well as the gradual process of diffusion where molecules move from a higher to lower concentration.

Step-by-step explanation:

The reason why smells travel slower than the speed of individual gas molecules is due to the way gas molecules move and interact. Gas molecules, while moving at high speeds (around 500 m/s), are in constant, random motion and frequently collide with each other and with their container walls. These collisions are elastic, meaning they do not lose energy, but they do change the direction of the molecules rapidly, causing a net movement of smell to be much slower than the actual speed of individual molecules.

Additionally, the process of diffusion contributes to the transport of smell. Diffusion is a molecular transport phenomenon where molecules spread out from an area of higher concentration to an area of lower concentration. This process is relatively slow compared to the molecular speeds because each individual molecule does not move directly from the source to the destination. It takes a zigzag path, colliding with other molecules, which makes the overall progression of smell gradual.