Dec. 5-9

This week, I learned about energy transfer through the three states of matter, and I learned about ETh and EPh energy.

Eph is the phase energy that is transferred when an object changes its state. So, if a solid changed to a liquid, there would be more phase energy since this made the particles move more freely. The particles are not rigidly structured like a solid. Rather, the density of the liquid is less than that of the solid because of the arrangement of the particles and the amount of space they are taking up. When a substance changes state from liquid to gas, the particles of gas are arranged even more freely and are spread out the most.

However, the problem is this: If solid changed to liquid without temperature, then why did it change state? The reason is because the amount of energy required to arrange the particles increases since more energy is required in a liquid to break bonds in solid in order to make the particles move freely about in contrast to the rigid and structured solid. In a solid, the particles move slower because they are in a crystalline structure, and it requires less energy to keep the particles closer together.

Eth is the thermal energy that is transferred when an object's temperature changes. The motion of the particles changes. As more energy is applied to a substance, its particles move faster and at greater distances and more freely. The greater the thermal energy, the more likely a substance is going to change state. However, enough energy has to be applied to a substance in order for it to actually change state. To change the motion and speed of the particles, the amount of energy changes the attraction between the particles. If the particles have a weak attraction, then the particles will move faster, and if they have a strong attraction, then they will move slower. Thus, in a liquid, the particles of a liquid have a weak attraction since they are not closely together. In contrast, a solid has the strongest attraction between the particles since they are the closest together. A gas has the weakest attraction because the particles are the farthest together.

What determines the attraction between the particles, though, is the term "field," which is the area around an object where non-contacting force can be exerted. Phase energy is stored in fields to arrange whereas thermal energy is stored in fields to change the motion of the particles.

I also participated in an experiment where I had to find the specific heat of copper. This week, my group and I had to come up with a procedure before we started. First, we had to measure the mass of the copper, then the water's mass, then, the temperature change of copper after putting it in water and the temperature change of water. Then, algebraically, I set the specific heat formula of water to the specific heat formula of copper equal to each other to figure out the specific heat (c) with E=mcΔT formula for both. Since the volume of water was 150 ml, and the density of water is 1g/ml, its mass was 150 g, the temperature change was 12.5ºC, and the specific heat is 4.18J/gºC. With the copper, the mass was 39.5 g, and its temperature change was around 480ºC. 
So, my mathematical procedure was this:

1. (39.5)(c)(Δ480)=(150)(4.18)(Δ12.5)
2. 17,520c=7,837.3
3. c=0.41J/gºC

The question remained: Was it the correct specific heat for copper? The algebraic process of showing how I found the specific heat was correct, but it may or may not have been correct. (this was mere speculation before I found out its specific heat of copper is 0.39J/gºC). So, I then thought of the possible sources of error. I considered that massed could have calculated incorrectly. Or, the temperature change could have been calculated incorrectly since the only way to determine this is to observe the color it changes to, which may have been mislabeled, contributing to incorrect temperature. It is also possible that I measured the water's temperature incorrectly.

I thought that since these were possible sources of error, I figured that if the mass of the copper were, then the specific heat of copper would be less than it should be or more than it should be. If the temperature change of the copper was miscalculated, then specific heat would be less than it should be or more than it should be. If the mass of water were miscalculated, then specific heat would be less than it should be or less than it should be. If the temperature change was miscalculated, of water were miscalculated, then specific heat would be less than it should be or more than it should be.