🧼🖐️

Why won't water alone wash off grease?

You eat a buttery snack. Your hands feel oily and slippery. You rinse them with just water… and they're still greasy! 😣

water just slides over the grease

Soap is the secret hero. Let's find out how this tiny bubble-maker grabs grease and washes it away! Tap Next to begin. 👉

First clue: water and grease are not friends 💧🚫🟡

Grease (oil, butter, fat) and water push away from each other. That's why a little oil floats on top of water and never blends in.

Tap each jar to peek inside!

Oil + Water
tap me
Sugar + Water
tap me
💡 Oil stays in its own layer — it won't dissolve in water. Sugar disappears — it does dissolve. Grease behaves like oil, so plain water can't carry it away.

Meet a soap molecule — it has two ends! 🪄

Every soap molecule looks like a tiny tadpole. It has a head and a long tail, and each end likes a different thing.

Tap the head and tap the tail to learn their secret jobs!

head tail
Head loves WATER 💧 Tail loves GREASE 🟡

Remember this: the head is a water-lover, the tail is a grease-lover. That double power is the whole trick! 🦸

Step 1: the tails dig into the grease 🟡

When you scrub with soap, all the grease-loving tails poke straight into the blob of grease. Drag each soap molecule so its tail sticks in!

Drag the 3 soap tadpoles onto the grease blob. 0 / 3 done

GREASE
🧽 Scrubbing helps the tails wriggle deep into the grease and break it into smaller bits.

Step 2: soap builds a tiny cage 🛡️

The tails hide inside the grease, so all the water-loving heads point OUT toward the water. They wrap the grease in a little ball called a micelle.

grease

Now the grease is trapped inside a friendly water-loving shell. Water is happy to carry the whole ball away! 🌊

Step 3: rinse — and it's gone! 🚿

Because the outside of the micelle loves water, the rushing water grabs it and washes the trapped grease right down the drain.

🫧
drain ⬇️
✨ No more grease on your hands — soap turned an "I won't mix" problem into an easy rinse!

You're the scientist — which part loves grease? 🤔

Quick check! A soap molecule's tail dives into grease. So what does the soap molecule's head like best?

More grease 🟡
Water 💧
Air 🌬️

Hint: the head is the end that points OUT so the water can carry the whole ball away.

🎉🧼💧

Brilliant! You know how soap cleans!

Next time you wash your hands, picture millions of tiny soap tadpoles grabbing the grease for you. 👏 Great learning, scientist!