And so it only consists of a proton in a nucleus. And so this is the hydrogen ion, aka. Also known as a proton. Now, usually these acid reactions, acidbased reactions take place in water because our body consists predominantly of water. And so we have a water molecule that will grab the H ion using one of its lone pair of electrons on the oxygen to form the following hydronium ion. Now, the next question is what exactly is the method by which we calculate we measure the hydrogen ion concentration inside solution.