🧪 What Is pH?
7th Grade ⚗️ Chemistry
pH tells how acidic or basic a liquid is, on a scale from 0 to 14. Pure water is 7, which is neutral.
The scale
Below 7 is acidic: lemon juice is about 2, vinegar about 3. Above 7 is basic (alkaline): baking soda in water is about 9, and soap is about 10. 7 is neutral.
Acids and bases
Acids often taste sour (like lemons). Bases often feel slippery (like soap). Strong acids and bases can burn skin, so scientists handle them carefully — never taste chemicals!
Testing pH
You can test pH with special paper strips that change color, or make an indicator at home from red cabbage juice, which turns pink in acids and green-blue in bases.
Quick quiz
What is the pH of pure water?
Lemon juice is…
Which number is most basic?