Since water droplets for on dust particles, where does the dust go when it rains?

When rain occurs, water droplets form around dust particles or other aerosols in the atmosphere. This phenomenon is part of a process called "coalescence," where tiny droplets combine to form larger ones. Here’s a detailed explanation of what happens to the dust during this process:

1. Dust Attachment: As moist air rises and cools, water vapor condenses onto dust particles, forming cloud droplets. Each droplet can capture multiple dust particles, effectively "collecting" them.

2. Droplet Growth: As more water vapor condenses around these droplets, they grow larger. This growth happens as more water molecules attach to the increasing mass of the droplet.

3. Precipitation: Eventually, when the droplets become sufficiently large and heavy, they overcome air resistance and fall to the ground as precipitation (rain).

4. Dust's Journey to the Ground: The dust that had been suspended in the atmosphere is thus brought down to the ground along with the water droplets. Often, this means that rain effectively cleanses the air by removing particulate matter like dust.

5. Final Destination: The dust, now mixed with the rain, will settle on the ground. In some cases, it may even contribute nutrients to the soil depending on its composition.

In summary, when it rains, the dust particles are collected by water droplets in clouds and are eventually brought down to the earth’s surface, helping to purify the atmosphere while potentially enriching the soil.