What is an atom? A- the smallest particle of an element. B- the negatively charged particle found in a cloud. C- the densely packed center of an element. D- An energy level with positive and negative charges

Calculate the ph at the equivalence point for the titration of a solution containing 150.0 mg of ethylamine (c2h5nh2) with 0.1000 m hcl solution. the volume of the solution at the equivalence point is 250.0 ml. kb forethylamine is 4.7 × 10−4 .