What is the change of frosting state?

The formation of frost is a sublimation phenomenon. Frost usually appears in the morning, when the water vapor on the surface meets the temperature below 0 degrees Celsius and becomes solid directly. The conditions of condensation formation are quite special. Generally, the concentration of gas is required to reach a certain requirement, and the temperature is lower than freezing point, such as water vapor below 0 degrees Celsius. The reason for the formation is generally a sharp drop in temperature or sublimation.

Scientifically speaking, frost is made up of ice crystals, similar to dew. When the relative humidity in the air reaches 100%, water is separated from the air. The only difference between them is that the dew point (the temperature at which water vapor liquefies into dew) is higher than the freezing point, while the frost point (the temperature at which water vapor condenses into frost) is lower than the freezing point, so frost will only appear when the near-surface temperature is lower than 0℃. Frost, frost and first frost are not the same thing, but three different concepts. "Frost" refers to a white ice crystal formed by condensation of water vapor on the ground in cold weather; "Frost" refers to a common agricultural meteorological disaster phenomenon; The "first frost" solar term refers to the season that reflects the sudden drop of temperature, while the "first frost" does not mean "frosting", but refers to the cold weather.