Introduction to the pH Scale

What you’ll learn to do: Demonstrate familiarity with the pH scale

Most people are familiar with the words acid and acidic—whether it’s because of acid rain or acidic foods like lemon juice. However, fewer people are aware of acid’s opposite: base (also called alkaline). Basic substances include things like baking soda, soap, and bleach. Distilled water is a neutral substance. The pH scale, which measures from 0 to 14, provides an indication of just how acidic or basic a substance is.

Most parts of our body (excluding things like stomach acid) measure around 7.2 and 7.6 on the pH scale (a 7 is neutral on the scale). If foreign strong substances dramatically change this pH, our bodies can no longer function properly.

In this outcome, we’ll learn about acids and bases, and what impact they can have on living systems.


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