What’s Really Happening?

Oil and water do not like to mix.

The oil floats on top because it is less dense than water.

When the fizzy tablet touches the water, it releases tiny bubbles of carbon dioxide gas.

These bubbles stick to the coloured water droplets and carry them upward through the oil.

When the bubbles reach the top, they pop and release the gas.

Without the bubbles, the coloured water becomes heavier again and sinks back down.

That’s why the blobs keep rising and falling like a dancing lava lamp!

Why Do The Blobs Move?

The secret is the gas bubbles.

The bubbles act like tiny life jackets that help the coloured water float.

When the bubbles burst at the surface, the water loses its lift and sinks again.

The cycle repeats over and over until the tablet stops producing gas.

Real-World Science

Scientists use ideas about density and gases in many real-world situations, including:

• Hot air balloons floating through the sky

• Submarines rising and sinking underwater

• Lava lamps creating moving blobs

• Fish using swim bladders to control their depth

The same science is happening inside your test tube!

Curiosity Question

If bubbles can lift coloured water through oil…

Could they lift something bigger?

What would happen if you used warm water, cold water, or a different fizzy tablet?

Try Next

• Does warm water make the blobs move faster?

• What happens if you add more tablet?

• Can you make the blobs larger?

• Does a different oil change the result?

Try next

• See the same oil-water boundary create a completely different kind of spectacle → [Comet Collisions]

• Watch CO₂ bubbles do the same lifting trick with a different passenger → [Dancing Raisins]