density and molecules

This week we learned about how water molecules work. When they are warm they move around alot. When they are cold they stay still. Mr. Finley put water in a glass bottle and then put a cork on top. He then put it over a flame and the cork flew off. This is because the water molecules moved up and pushed the cork off. He also put water in a bottle lew out a flame into it. Then he squeesed the bottle and when he let go, there was fog. This is because when there is more presure the particles move faster and there is evaporation. When there is low presure the particles go slow and there is less condensation or no fog. We also learned about density. Volume is how much space something takes up. If something is filled with particles and they are PACKED IN, IT IS DENSE AND HAS MORE mass.( sorry for the caps lock).