Let's say that the chemical groups on the amino acid have the following properties: pKa of terminal amine = 9.6 pKa of R-group = 6.0 pKa of terminal carboxylate = 2.3. When considering the entire population of a 1M aqueous solution of the amino acid at pH 9.6, the charge character of terminal amines will be predominately negatively charged equally negatively charged and neutral predominately neutral equally positively charged and neutral. equally negatively and positively charged predominately positively charged no acid have the following properties: