What is the percent of water present in the hydrated salt? Mass of Hydrated salt = 12.28 g
Mass of Anhydrous salt = 9.14 g

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8