At the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror. This line is known as a normal line (labeled N in the diagram). The normal line divides the angle between the incident ray and the reflected ray into two equal angles. The angle between the incident ray and the normal is known as the angle of incidence. The angle between the reflected ray and the normal is known as the angle of reflection.
Even if the water were to be cooled from the bottom, the coldest water would float to the top and when the whole pond became 0Â°C the ice would float to the top as it formed. In some cases where rocks are below the freezing point (exposed to the air part of the time, ice can form and stick to the rocks under water.
(This pattern is what you see if you look at ice crystals.) So, when water freezes, the molecules take up more space, and the ice ends up being even /bigger/ than the water was. If you were to put that water in a closed container in the freezer, then it would still get bigger. What happens to the container depends on what sort of a container it is. For example, if the container were made of thin plastic, it would probably stretch a bit as the water freezes.