Week 3 – Moving Particles

Tuesday:  We observed the diffusion of perfume in air.  We concluded that the diffusion must be occurring because particles of air are moving, they bump into the scent particles, which cause them to spread out throughout the room.

We then observed a drop of dye in both cold water and hot water.  Here they are after a couple minutes:

2015-06-22 15.43.352015-06-22 15.43.39

We concluded that dye spread out faster in hot water, meaning the particles of hot water are moving faster than cold.  We decided that temperature is simply how fast particles move.  When things are hot, the particles move faster.  When things are cold, they move more slowly.

Monday: We measured the temperature of ice-water as it was heated and produced a graph like this one:

Next:  We determined that the graph included two types of energy:

Thermal Energy (Eth) = energy of the motion of the particles, which depends on their speed (temperature).  As temperature increases, thermal energy increases.

Phase Energy (Eph) = energy of the attraction between particles due to the phase or state of matter (solid, liquid, or gas).  Solids have a low amount of phase energy, liquids have a medium amount, and gases have the highest amount.  You must add energy in order to move a substance from solid to liquid and liquid to gas.

We represented these distinctions for several situations on the homework.  You can check out this webpage for some discussion and examples: http://blog.msbethea.com/?p=1138

Homework: LabPacket – Week 3

Lab Packet: Practice – Week 3 – energy bar graphs


Use these videos for key understandings about our model of matter:


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