Why does ice float on water?

1. When water freezes, its molecules arrange in an open hexagonal lattice. 2. This open arrangement makes ice less dense than liquid water. 3. By Archimedes' principle, less dense objects float on denser fluids. 4. So ice floats on water because it is less dense. 5. About 90 percent of an iceberg lies submerged because density ratio is about 0.9. _Source: Selina Concise Physics ICSE Class 8, Ch 1 'Matter'_