Frozen lakes look really fun to ice skate on, although it also looks dangerous. It is also really interesting how they Freeze over. Normally any liquid or gas sinks when it gets cold, so you would expect to find the ice at the bottom of a lake, but water has pretty cool properties that allows ice to form on the surface of lakes.
When the average temperature of the water in a lake gets to about 4°C and the temperature continues to drop, the cooler water rises to the surface because it becomes less dense. When this water reaches 0°C it starts to freeze at the top of the lake making a large sheet of ice. If the water temperature continues to drop, the ice sheet gets thicker, until it can carry a lot of weight. When it becomes thick enough a person is able to skate on it without fear of it breaking.
