science+discoveries+of+February+mep

2-10-15 the phase changes of water molecules. there are 6 phase changes in water molecules. Freezing, melting,condensation, deposition, sublimation, and evaporation. to reach any of these phase changes you have to either add energy or take it away. going from a solid to a liquid is melting. you have to add energy (heat) to melt the solid then it becomes a liquid. going from a liquid to a gas is called evaporation. your adding even more energy than before. going form a solid directly to a gas is called sublimation. your adding so much energy to the molecules that they overcome the attractions and escape to the air as water vapor. going from a gas to a solid is called deposition the molecules slow down there energy so much they turn right back to a solid. going from a gas to a liquid is called condensation. your taking away energy and the water vapor molecules bump into a cold object slowing them down and attraction them again. going from a liquid to a solid is called freezing. to freeze something you have to take away energy (cool it) so the molecules have enough attractions and turn back to a solid.

2-20-15 why do we sweat? when our body temperature rises all 2.6 million of our sweat glads come to life to keep us cool. believe it or not the sweat glands sometimes evaporate taking the heat with them. when we sweat, our sweat glands produce precipitation. if you've ever played a sport you know that sweat sometimes does stink... why? actually its not the sweat that smells...its our body odor or B.O. our sweat comes from bacteria from our body breaking down the sweat glands to make the wetness. then our body "smell" takes over the stinking part. sweating in all isn't a bad thing. it is a sign of working hard.