Why Ice Floats
Water is special. Most things get smaller when they get cold. Water is different. When water turns into ice, it grows. It takes up more space.
Imagine a box of water. The water molecules move fast. They bump into each other. When water gets cold, it slows down. At zero degrees Celsius, water turns into ice. The molecules stop moving. They lock into a shape. This shape has gaps. The gaps make ice bigger than liquid water.
Because ice is bigger, it is lighter. Scientists call this density. Things that are less dense float. Things that are more dense sink. Ice is less dense than liquid water. That is why ice cubes float in your drink. That is why icebergs float in the ocean.
This is important for life. In winter, lakes freeze on top. The ice acts like a blanket. It stays on the surface. The water below stays liquid. Fish and plants can live in the deep water. If ice sank, lakes would freeze from the bottom up. The whole lake would turn into a block of ice. Life would be very hard.
Nature is smart. The way water acts helps life survive. Next time you see ice in your glass, look closely. You are seeing a science secret. The ice is light. It stays on top. It keeps the world below safe.
Do you know why ice floats in your water glass?