what is the difference between hail and ice pellets
Ice pellets Ice pellets are a form of precipitation consisting of small, translucent balls of ice. Ice pellets are smaller than hailstones[1] which form in thunderstorms rather than in winter, and are different from graupel ("soft hail") which is made of frosty white rime, and from a mixture of rain and snow which is a slushy liquid or semisolid. Ice pellets often bounce when they hit the ground or other solid objects, and make a higher-pitched "tap" when striking objects like jackets, windshields, and dried leaves, compared to the dull splat of liquid raindrops. Pellets generally do not freeze into a solid mass unless mixed with freezing rain. The METAR code for ice pellets is PL (PE before November 1998[2]).
Ice rink Modern rinks have a specific procedure for preparing the surface. With the pipes cold, a thin layer of water is sprayed on the sand or concrete to seal and level it (or in the case of concrete, to keep it from being marked). This thin layer is painted white or pale blue for better contrast; markings necessary for hockey or curling are also placed, along with logos or other decorations. Another thin layer of water is sprayed on top of this. The ice is built up to a thickness of 3/4ths an inch to 1 1/2 inches.[9] The industry standard in the NHL is around 1 1/2".