how many moels of benzoic acid, a monoprotic acid with Ka = 6.4 x 10^-5 must be dissolved in 500. mL of water to make a solution with a pH=2.50

Consider the nuclear equation below. 239 > x + 4 he 94 2 what is x? 1.235 cm 96 2.243 u 92 3.235 u 92 4.243 cm 96

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins