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Sir please define ice crystals, snow, ice pellets, hail, and frost,dew.

Ice crystal is a barely visible crystalline form of ice that has the shape of needles, columns or plates. Ice crystals are so small that they seem to be suspended in air. Ice crystals occur at very low temperatures in a stable atmosphere.

Snow is precipitation in the form of flakes of crystalline water ice that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless subjected to external pressure.

Hail is a form of solid precipitation. It consists of balls or irregular lumps of ice, each of which is referred to as a hailstone.Hail formation requires environments of strong, upward motion of air with the parent thunderstorm (similar to tornadoes) and lowered heights of the freezing level.

Ice pellets are a form of precipitation consisting of small, translucent balls of ice. Ice pellets are usually smaller than hailstones and are different from graupel, which is made of rime, or rain and snow mixed, which is soft. Ice pellets often bounce when they hit the ground, and generally do not freeze into a solid mass unless mixed with freezing rain.

Frost is the solid deposition of water vapor from humid air. It is formed when the temperature of a solid surface is below the freezing point of water and also below the frost point.The size of frost crystals varies depending on the time they have been building up and the amount of water vapour available.


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