Question

we get the smell of perfume sitting several meter away, explain it.

Answer 1

this is because of the phenomenon of diffusion and diffusion means intermixing of substances to create uniformity and it is highest in gas

Answer 2

We get smell of perfume sitting several meters way because perfume is a highly volatile substance. It has the tendency to move from one place to another. So, as the result we get the smell of perfume sitting several meter away.

One of the other example is smell of food when it is being cooked. Here comes the same reason that when food particles get heated up there molecular force becomes less. So, they tend to move and we get the smell sitting several meters away.

Hope it works!!!