Which term describes the process of water droplets joining together to form larger droplets?

Coalescence accurately describes the process where small water droplets collide and merge to form larger droplets. This phenomenon is essential in the development of precipitation within clouds. As the larger droplets form, they become heavy enough to overcome updrafts in the atmosphere, leading to rain.

The other terms relate to different processes. Depositation refers to the transformation of water vapor directly into ice without passing through the liquid phase, commonly observed in the formation of frost. Evaporation is the process by which liquid water turns into water vapor, losing energy in the process. Condensation involves water vapor transitioning back to liquid form, often observed when water vapor in the air cools and forms dew or clouds. Each of these processes plays a role in the water cycle but does so in different contexts from coalescence.