Acids, Bases & pH
📋 What it is
The pH scale (0–14) ranks how acidic or basic something is; 7 is neutral.
🗣️ Coach says
Acids (lemon, vinegar) taste sour and sit low on the pH scale; bases (soap, baking soda) feel slippery and sit high. Pure water is neutral at 7. Indicators like red cabbage juice change colour to reveal pH. Mix an acid and a base and they neutralise each other.
🧠 Memory hook
pH 0–14: low = acid, high = base, 7 = neutral. Acid + base → neutralise.
😂 Giggle
Why was the mole of oxygen molecules excited?
It was going to the Avogadro's number party — 6.022 times 10 to the 23rd guests were invited!
😲 Whoa!
Your stomach acid is so strong (around pH 1–2) it could dissolve metal — a special mucus lining is all that stops it from digesting your own stomach.
✅ Quick check: On the pH scale, is a strong acid closer to 0 or to 14?
Say your answer out loud first — then reveal.
Closer to 0 — low pH means acidic; high pH (toward 14) means basic.
The pH scale runs acidic (low) to basic (high), with 7 neutral.
🧪 Try it! (2 minutes)
Dip red cabbage juice (or a pH strip) into lemon juice, then soapy water. Watch the colour reveal acid vs base.