Answer:In regards to writing the formula, we know that magnesium has a charge of 1+ and sulfate, SO4, has a charge of 1-. Sulfate is a polyatomic ion so the charge of the whole thing is (SO4)1-. When you combine them you end up with MgSO4 and the "heptahydrate" is seven water molecules.
Explanation:
Classification of the Elements. The next thing in our review is to classify the elements into three groups. These three groups are: metals, nonmetals, and inert gases. Let's look at where these groups are located on the periodic table and correlate them with the ability to lose and gain electrons.
No, the water is not different it is just that the units of measurement in the US is different then those units in Europe. This is similar to how the US uses miles and Europe uses kilometers