The notation  hydrated compound ânH2O , where n is the number of water molecules per formula unit of the salt, is commonly used to show that a salt is hydrated. The n is usually a low integer, though it is possible for fractional values to occur. For example, in a monohydrate n is one, and in a hexahydrate n is 6.
When does spring start? How you define the first day of spring depends on whether you follow the astronomical or meteorological seasons. This year, spring will take place between March 20 and June 21, if you use the astronomical method. But it starts slightly earlier, between March 1 and May 31, if you follow the meteorological calendar.
First Day Of Spring 2017- When is Spring Equinox 2017. Exactly when is the first day of spring 2017 (non leap year) officially. Crazy info of spring equinox 2017; how many days until spring 2017 countdown, facts, calendar, spring 1st day in usa, uk, canada, australia, northern hemisphere, everything you should need to know.