O.J. Simpson, also known as âThe Juiceâ, is a former professional football player that was a member of the NFL for the Buffalo Bills and San Francisco 49ers. After being selected with the first overall pick of the 1969 NFL Draft, Simpson dominated the league at running back and became the first athlete to rush for more than 2,000 yards in a season.
water does expand when it freezes because water is polar and so pushing the molecules close together actually makes them feel a force of repulsion, hence they move apart, so it expands. In general, materials expand when heated and contract when cooled...you are trying to apply the logic that if water expands when its cooled then it must contract when heated...but this is only true between the liquid and solid states. If you heat water to be a gas (steam) then it expands just like normal materials do when heated. When heated you put more energy into the atoms so if you put them in a box it will push harder against that box (which you see as pressure) or if you allow the box to expand then it will to equalize the pressure (i.e. expanding makes the pressure less).
The water at the bottom of the pot heats up first. This causes it to expand. Since the warmed water has a lower density than the water around it, it rises up through the cooler, dense water. At the top of the pot, the water cools, increasing its density, which causes it to sink back down to the bottom. This up and down movement eventually heats all of the water.