In diffusion, molecules spread out
condense

In diffusion, molecules spread out condense

Spread out

Explanation:

If you were to spray perfume, you would be able to smell if you moved slightly away from where you sprayed it as the molecules have diffused.

correct answer is a. and d.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave