Difficulty: Easy
Correct Answer: dew
Explanation:
Introduction / Context:
This question tests knowledge of weather processes by asking which phenomenon is not a form of precipitation from clouds. Precipitation includes various ways that water falls from the atmosphere to the Earth surface, such as rain, snow, sleet and hail. Dew, fog and mist are related to condensation but behave differently. Recognising which option does not represent precipitation helps clarify the difference between water condensing in the air and water falling out of clouds as drops or ice.
Given Data / Assumptions:
Concept / Approach:
Hail is clearly a form of precipitation. It consists of balls or lumps of ice that fall from cumulonimbus clouds during thunderstorms. Fog and mist are both forms of suspended water droplets near the surface, formed by condensation in the air. They reduce visibility but do not fall from clouds as rain or hail does. Dew, on the other hand, forms when water vapour condenses directly on cool surfaces, such as grass or metal, usually at ground level during calm, clear nights. It does not involve droplets falling from clouds or even condensing as suspended droplets in the air. Because dew is a deposit on surfaces, it stands out as not being precipitation from clouds.
Step-by-Step Solution:
Step 1: Recall that precipitation is water that falls from clouds to the ground in forms such as rain, snow or hail.
Step 2: Recognise that hail is ice that falls from clouds and therefore is a form of precipitation.
Step 3: Understand that fog and mist are collections of tiny droplets suspended in the air near the ground and form by condensation, not by falling from clouds.
Step 4: Note that dew forms directly on surfaces when they cool below the dew point, with no cloud or falling movement involved.
Step 5: Conclude that dew is fundamentally different from precipitation and is the correct answer.
Verification / Alternative check:
To verify, imagine each phenomenon. Hail clearly falls and can strike roofs and vehicles, sometimes causing damage, which fits the idea of precipitation. Fog and mist hang in the air, reducing visibility but not falling as drops; however, questions often treat them as outcomes of condensation in the lower atmosphere rather than precipitation. Dew is observed as tiny droplets on grass, car roofs or spider webs in the early morning, and it is obvious that these droplets did not fall from the sky. Weather charts and textbooks classify dew under direct condensation rather than under rainfall or other forms of precipitation. This confirms that dew is the different process among the options.
Why Other Options Are Wrong:
Fog consists of very tiny water droplets suspended in air and is generally considered a form of condensation, but in some contexts it is grouped under atmospheric moisture phenomena rather than precipitation; still, it is closer to atmospheric processes than dew, which forms on surfaces.
Mist is similar to fog but less dense and is again an atmospheric phenomenon caused by condensation of water vapour in the air.
Hail is a true form of precipitation because solid ice particles fall from clouds to the ground.
Common Pitfalls:
Students sometimes confuse all forms of condensed water as precipitation, failing to distinguish between water falling from the atmosphere and water forming on surfaces. Another mistake is to think fog and mist are precipitations because they involve water in air, even though they do not literally fall as drops. Dew can also be misunderstood, as some might think the water comes from the air above rather than condensing directly on surfaces. To avoid confusion, remember that precipitation falls from clouds, whereas dew forms directly on surfaces without falling. This makes dew the odd one out in this set of options.
Final Answer:
The phenomenon that is not a form of precipitation from clouds is dew.
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