What are elements with atomic numbers above 95 called?

First, there is nothing inherently different about transuranic elements. They do share some common characteristics. As a class, they are all radioactive. But that's also true of all elements above atomic number 82 (lead) (Pb-208 being the heaviest stable isotope known). And radioactivity is actually far more common than stability if you look at all the known nuclides. The transuranics also share the trait that they will undergo nuclear fission. We'll look at that later, also check the link for more info. But these traits are not unique to the transuranics. Uranium is also fissionable, and elements as light as atomic number 88 (radium) may undergo fission (but not very efficiently). We also should keep in mind that there are many isotopes that are much lighter than uranium which are only available by "artificial" means. So, again, there's no unique property that applies only to "man-made" isotopes or transuranic elements.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"