What is the correct definition of pH?

how basic a solution is

the concentration of potassium ions in solution

how acidic a solution is

the concentration of hydrogen ions in solution

Aprotein molecule in an electrophoresis gel has a negative charge. the exact charge depends on the ph of the solution, but 30 excess electrons is typical. what is the magnitude of the electric force on a protein with this charge in a 1600n/c electric field? write in two significant numbers, and also in newton