where he studied ion concentration on proteins and devised a simple way to express the concentration of hydrogen ions: the pH scale. Introduced in 1909, the pH scale — officially, the power of ...

In some communities, it takes a lot of soap to properly wash your hands. This occurs in places with "hard" water, where high levels of calcium, magnesium and other alkaline minerals are found in ...

And because the concentration of hydrogen ions was particularly important, he introduced the pH-scale as a simple way of expressing it in 1909. Taking back to the chemistry lessons from school ...