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.
Mar 20, 2015 First day of spring 2015 Mar 19, 2016 First day of spring 2016 On www.almanac.com the starting dates of the seasons is given and reason for them, and also why different seasons start at different times and dates based on the time zone you're in, etc., and if you want to try experiments like balancing an egg on the vernal equinox or some other eqinox, etc.,