Solid silver nitrate is added slowly to a solution that is 0.0010 M in sodium chloride and 0.0010 M in sodium bromide. What % of the bromide ions remain in solution, i.e., unprecipitated, just before silver chloride begins to precipitate? Ksp for AgCl=1.8x10^-10, Ksp for AgBr=3.3x10^-13