When you were outside the city in summer, you watched how sometimes fog descends on the earth in the evening.

When you were outside the city in summer, you watched how sometimes fog descends on the earth in the evening. Under what conditions does it form? Under what conditions does dew appear on the grass?

Fog, dew and frost are of the same origin – they form as a result of condensation. Tiny droplets of moisture are always present in the air. In summer, in the air heated by the sun, this moisture is not visible. In the evening or at night, when the sun sets over the horizon, the air gradually cools down and the earth’s surface cools. When the surrounding air is cooled, this moisture in the form of vapor will condense and turn into a liquid state, that is, into water. This is how dew and fog will form on the grass. If the temperature drops to negative values, the dew will turn to frost.