1 year ago
Last edited at 8:32PM on 5/24/2012
It is less dense than water. The hydrogen bonds cause it to expand at freezing temperatures, which makes it less dense. Kammo is also correct, the hydrogen bonds are the reason the crystal lattice structure forms.
1 year ago
Last edited at 8:35PM on 5/24/2012
The common answer given is that "it is less dense than water". This only begs the question though. The more complete answer is a combination of Archimedes' Principle and Newton's laws of motion. If you need more details, I can elaborate. Otherwise, you may look this up.
Ice floats because it is about 9% less dense than liquid water. In other words, ice takes up about 9% more space than water, so a liter of ice weighs less than a liter water. The heavier water displaces the lighter ice, so ice floats to the top. One consequence of this is that lakes and rivers freeze from top to bottom, allowing fish to survive even when the surface of a lake has frozen over.
Saying frozen water is more dense than water doesn't answer anything. Everything less dense than water floats in water. What we need to be answering is "How does freezing water cause it to lose density?" Kathy Wollard explains it well here. http://www.word-detective.com/howcome/waterexpand.html