What is moisture condensed from the atmosphere and deposited in the form of small drops upon any cool surface called?

The correct answer is dew, which refers specifically to the moisture that forms when water vapor in the air condenses into small droplets on cool surfaces such as grass, leaves, or car windows. This process typically occurs during the night or early morning when temperatures drop, causing the air close to those surfaces to cool as well.

Dew is particularly important in nature as it provides moisture to plants and can be a key factor in certain ecosystems, especially in arid regions where rainfall is scarce. Understanding this concept is critical for recognizing how moisture behaves in the environment and its effects on various biological and ecological processes.

The other terms presented—rain, fog, and humidity—refer to different phenomena. Rain is liquid water that falls from clouds in droplets larger than dew, while fog is a thick cloud of tiny water droplets suspended in the air near the ground, which reduces visibility. Humidity is a measure of the amount of water vapor in the air, but it does not describe a specific physical occurrence like dew does.