🍋🧼

Acids and Bases: Lemon vs Soap

Everything around us is made of tiny bits called chemicals. Some are acids and some are bases.

Acid  A lemon is an acid. Acids often taste sour. 😖

Base  Soap is a base. Bases often feel slippery. 🫧

Let's become little scientists and find out how to tell them apart — no tasting soap, promise!

Tap each thing to discover its secret

Acids and bases give us little clues with our senses. Tap the cards below to reveal each clue.

🍋
Lemon
tap me
🧼
Soap
tap me
🍊
Orange juice
tap me
Tap all three cards to see every clue!

The magic cabbage juice 🥬

Scientists use a special juice (from red cabbage!) that changes colour to spot acids and bases. We call it an indicator.

Drip a liquid into the beaker and watch the colour change:

Pink = acid Purple = neutral Green = base

You be the scientist 🔬

We dripped cabbage juice on a slice of lime (a green sour fruit). Lime is very sour, like lemon.

What colour will the juice turn?

Pick the colour you think is right.

Acid bin or Base bin?

For each item, tap 🍋 Acid or 🧼 Base. Sour things are acids; slippery, soapy, cleaning things are usually bases.

🍋Lemon
🧼Hand soap
🍅Tomato
🦷Toothpaste
🥤Fizzy drink
🫧Shampoo
Sorted: 0 / 6

The pH ruler 📏

Scientists measure acids and bases on a number line called pH, from 0 to 14.

0–6 acid 7 neutral 8–14 base

Slide to 7 — the neutral middle, where water sits:

🍋 2 💧 7 🧼 10
pH = 0
🎉🧪🏆

Brilliant work, young scientist!

Here's everything you discovered:

Next time you squeeze a lemon or wash your hands, you'll know the chemistry hiding inside. Keep being curious! ⭐