Why Are Ice Cubes Cloudy in the Middle?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why are ice cubes cloudy in the middle?

The Big Idea

Ice cubes are cloudy in the middle because freezing pushes tiny bubbles of air to the center! Water freezes from the outside in, and the air and minerals that were dissolved in the water get squeezed toward the middle. They get trapped there, and that makes the cloudy core.

Freeze Inward

Step one: the outside freezes first. The cold freezer air touches the edges first, so they turn to ice before the middle does. The ice grows inward, like a shrinking puddle.

Air Pushed In

Step two: the extras get pushed along. Tap water holds dissolved air and minerals. Solid ice cannot fit them in, so it pushes them toward the last liquid water in the middle.

Cloudy Core

Step three: the middle freezes last. Now the air and minerals are locked inside, and they scatter light. That scattered light is what makes the center look white and cloudy.

A Closer Look

Let's take a closer look! We start with tap water that has air mixed in. The edges freeze first and push everything inward. The air gets trapped in the very middle. And the trapped air makes the cloud you see.

Quick Facts

Quick facts! Slower freezing can make clearer cubes, because the air has more time to escape. Ice floats in your glass because water expands as it freezes. Cloudy ice is safe to use, and it is just full of tiny bubbles. Boiling water is hot, so a grown-up must do the boiling.

Think Like a Scientist

Now, think like a scientist! Freeze one tray of tap water. Freeze a second tray of water that a grown-up boiled and let cool. Compare how clear the cubes are. Which tray made clearer ice?

Outro

Cloudy ice is just trapped air and minerals. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!