Correct Option
The correct option is 2 only
Explanation
Fog and mist are forms of condensation that occur near the Earth's surface. They form when the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, causing condensation to take place on fine dust particles (hygroscopic nuclei). The primary distinctions between them are moisture content and visibility.
Statement-wise Analysis
- Statement 1 is Incorrect: Mist contains more moisture than fog. Mist is frequent over mountains or areas where rising warm air meets a cold surface, leading to high moisture accumulation.
- Statement 2 is Correct: In mist, each hygroscopic nucleus contains a thicker layer of moisture compared to fog. This is because mist forms in conditions of higher humidity, allowing more water to condense around each particle.
- Statement 3 is Incorrect: Fogs are generally drier than mist. While fog significantly reduces visibility (often to less than 1 km), it contains less suspended water per unit volume compared to mist.
Key Takeaway: Mist contains more moisture and has a thicker layer of water on nuclei compared to fog, which is drier; however, fog restricts visibility more severely than mist.