AP®︎ Chemistry. Acids and bases. AP®︎ Chemistry. Acids and bases ... (Opens a modal) pH, pOH, and the pH scale (Opens a modal) Brønsted-Lowry acid base theory (Opens a modal) Brønsted-Lowry definition of acids and bases ... economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the ...