Below are data on the first four ionization energies for a fictitious element X.

First ionization energy = 500 kJ/mol
Second ionization energy = 2000 kJ/mol
Third ionization energy = 3500 kJ/mol
Fourth ionization energy = 25000 kJ/mol

From the data, which of the following statements is incorrect?

A. X could belong to Group III A
B. The fourth ionization energy is much greater than the third ionization energy because X3+ consists of a noble-gas core or a pseudo-noble-gas core
C. The third ionization energy is greater than the second ionization energy because X2+ has a bigger charge than X-
D. X could belong to Group IIIB
E. X could belong to group VA.

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)