Why do ice cubes float to the top of a glass of water? A. Ice has a higher density than liquid water. B. Ice has a lower density than liquid water. C. Ice is very light. D. Water has buoyancy.

Ice cubes float because they have a lower density than liquid water. When water freezes, it expands, causing the ice to be less dense and therefore able to float on top! This nifty little quirk of nature is crucial for aquatic life, as it means lakes and ponds freeze from the top down, allowing fish and other creatures to stay safe beneath the ice. When you drop an ice cube into your drink, it reminds us of Archimedes' principle - which tells us that a body submerged in a fluid experiences an upward force equal to the weight of the fluid it displaces. So, as the ice cube displaces water, the buoyant force keeps it afloat while cooling your drink!