Q10. Why do icebergs float in the sea?
Ans. WHEN MOST THINGS GET COLDER, THEY CONTRACT, AND WHEN MOST LIQUIDS freeze they get very much smaller. Water is unique in that it contracts only down to a certain temperature, 4oC (39.2oF). If it gets colder still, it begins to expand, because the special bonds between the hydrogen atoms in the water begin to break down. When it freezes, water expands so much that ice is actually lighter (less dense) than water, so ice floats. But it is only a little lighter, so icebergs float with almost nine-tenths below the water line- which is why they are so dangerous to ships.