4.Based on the solubility rules, which one of the following should be soluble in water? (A) AgBr (B) AgCl (C) Ag2CO3 (D)AgNO3 (E) Ag2S

6.Calculate the wavelength of the light emitted by a hydrogen atom during a transition of its electron from the n = 4 to the n = 1 principal energy level. For hydrogen J(1/n2 ), C = 3 x108 m/s, h = 6.626 x JS. (A) 97.3 nm (B) 82.6 nm (C) 365 nm (D)0.612 nm (E) 6.8 nm