Why does ice float on water?

Ice floats on water because it is lighter than the same amount of liquid water.

Imagine you have two cups, one filled with ice cubes, and one filled with water. Even though they look about the same size, the ice cube cup feels lighter when you lift it. That’s because ice takes up more space than water, but it weighs less. It's like having a big, fluffy pillow compared to a small, heavy rock, the pillow might take up more room, but it doesn’t weigh as much.

When water freezes into ice, its molecules move apart and form a special shape. This makes ice less dense than liquid water. Density means how much something weighs in a certain amount of space. Since ice isn't as packed together as water, it floats on top like a toy boat on a lake.

Think of making a snowman, the snow is fluffy and light. If you melt that same snow into water, it becomes more compact and heavier. That’s exactly what happens with ice and water!