What is the percent of copper found in Cu2SO4

What is important to study for nios grade 12 chemistry? i have only one month left.

100 points answer quick the table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

The solubility of barium nitrate is 9.02 g/100 g h2o at 20°c. a 15.2 g sample of barium nitrate is added to 200.0 g of water at 20°c. is the solution saturated, unsaturated, or supersaturated? a. unsaturated b. saturated c. supersaturated