Write the formulas for the following compounds:
(a) Rubidium nitrite,
(b) Potassium sulfide,
(c) Sodium hydrogen sulfide,
(d) Magnesium phosphate,
(e) Calcium hydrogen phosphate,
(f) Potassium dihydrogen phosphate,
(g) Iodine heptafluoride,
(h) Ammonium sulfate,
(i) Silver perchlorate,
(j) Boron trichloride.