Energy

1.Max Planck and his theory of energy?

Before Max Planck’s discovery, people had no idea what light consisted of. They did not realize that light was actually made of little particles called photons. He, also, created the formula E=hv, meaning that energy is equal to Planck’s constant (h=6.26x10-34) and the frequency of the radiation. He had discovered this when he was working on a problem of how the radiation an object emits is related to its temperature.

*If the energy has a low wavelength than its intensity is better than that of a low wavelength.
This theory helped Bohr create an accurate formula for the energy levels of an atom, which explained how electrons could jump from one orbit to another by emitting or absorbing energy.

*Ignore their explanation. So basically an electron orbits around the nucleus. Each orbit has a different amount of energy needed for an electron to jump into it. The greater distance an electron is away from the nucleus the more energy an electron needs.
Personally, I enjoyed learning about Max Planck’s theory, because even though he didn’t believe it was revolutionary back then, it actually had made a huge impact in how we see energy.

2. Atomic Model

In J.J Thomson's Plum Pudding Model, the pudding represented a positively charged filling with negatively charged particles floating in it, the raisins. The positively charged filling had practically the same consistency in the atom/ It had remained the dominant theory of the atom until 1908.

Rutherford, a former student of Thomson, believed that instead of just floating there in 'soap', they would orbit around a central nucleus. He had discovered when he shot positively charged particles through gold foil. If Thomson's theory of the atom were correct, the rays would have passed through normally. However, Rutherford noticed that some of the rays had bounced off something solid, which he concluded to be a central nucleus, and proved that Thomson's theory was incorrect in that part. He was correct about there were negatively charged particles called electrons, though. It was called the Planetary Rotation, because he said that it resembled the sun and how the planets revolve around the sun, just like how the electrons are forced to orbit around the central nucleus, due to the fact that it contained positively charged protons.

His theory seemed pretty solid, however, they was one issue. The orbiting electrons would eventually collapse, making the atom unstable, because of the energy expended would cause it. Hence Bohr's explanation of Stability. He proposed a quantum theory of electron rotation. When an atom would gain or lose energy, the electrons would either jump to the higher or lower orbits and they would travel in definite orbits around the positive nucleus. It was a hard concept to understand, but later experiments on the hydrogen atom would prove his theory to be correct. This completed the Planetary Rotation and replaced Thomson's atomic model.
I actually enjoyed learning about this, not that I don't enjoying learning in chemistry, but I do like knowing how our idea of the atom started off as a positive filling with electrons just floating about to what we know now today. I most enjoyed reading about the Planetary Rotation theory of Rutherford, because it made it easier to understand that an atom was like our solar system.
3. Spectroscopy
The light was caused by a change in the energies of the orbiting electrons, like an electron dropping from an outer ring to one closer to the central nucleus. Before I explain why, in the cases that we observed spectroscopy through flame tests, life-savers, etc., were not a complete, continuous rainbow of colors, let me first explain what a continuous spectrum is. When you shine a white light through a prism, you'll notice a rainbow colors and the reason for it is dispersion, which happens, because light of different wavelengths refracts by different amounts inside of the prism.

(*The results of the dispersion of a light by a prism, creating a rainbow.)
So then how come the when we tested out these other things, we got a spectrum that contained gaps, that were not a continuous spectrum. The gaps between a spectrum are called absorption lines. Certain elements, such as hydrogen and helium, when something is shone through, they absorb the energy, but only the electromagnetic waves that are just the 
(*Elements need this kind of energy, hence the
reason you can't see this specific color when passed
through the specific element. Absorption lines...)
right color to correspond with the energy that they need. Then there is the emission spectrum, the polar opposite of the absorption spectrum, where instead of getting a continuous spectrum of colors with only a few particular colors missing, you only get to see a few colors.
My explanation might explain the reason why you can't see certain colors when you pass light through a type of element.
I liked learning about the light spectrum, because it was very intriguing to see the rainbow and each individual color, though my favorite was the flame test, because I liked how the spectrum moved like the flame and fluttered very prettily.

Chemistry 2/29

1. Molecular Model Lab
We had made molecules of reactants out of this kit we were given. We were supposed to make as many complete products of the reactants as we could. Basically, you had to write how many of the reactants we had used and the products that were created and if you could reduce it, then you were supposed to. An example would be Na+O2= Na2O. To balance the equation you need to add another product for there to be two oxygens. Now there are four sodiums so you have to make four of the sodiums. 4Na+O2=2Na2O.
During this lab, I learned the beginning of balancing equations, though it was more of a simpler version than what we were going to do later. I had remembered the Law of Conservation of Matter, how matter is neither destroyed nor created, which is an important rule for balancing equations.

2. Balancing Equations

I had already described the basics of balancing equations, but why do we have to balance equations? The reason is because we need to abide by the Law of Conservation of Matter. How do you do it? 

1) Write the correct formula for each reactant and product. Diatomic molecules, such as H, N, O, F, Cl, Br, and I, need to be doubled, because they cannot stand alone, hence the reason they're called diatomic molecules. 

2) Adjust the coefficients, so that the number of reactants matches the number of atoms in the products.

Some hints provided to me by my teacher are: 

1)Adjust the coefficients of a single species, such as K or O2, last. 

2)Sometimes the temporary use of a fraction/decimal is helpful. 

3)If there are polyatomic ions on both sides of the arrow, balance them as units. 

I think that this part of the unit was my favorite, because I love balancing equations. I like how I don't even need to use the steps to figure out the answer. I just use mental math to do so, though using the step by step does help and I do use it to check my answer. I liked learning how to balance equations and I love to do these for fun whenever I'm bored. 

3. Predicting Products Lab

The point of this lab was to be able to predict the product of a chemical reaction using certain reactants. We were given instructions to do 9 different labs each using different reactants and figure out the product. We were supposed to use splint tests to figure out the gas product and litmus paper to figure out if the product was either a base, an acid, or neutral. We were also supposed to decide which energy was used, whether it was from system to surroundings or surroundings to system, and the reaction type, which we didn't know until the experiments was finished. Using all of this, you can predict the product. 

We learned the gas tests, that you have H2 if the burning split pops, that you have O2 if a glowing splint reignites, and that you have CO2 if a burning split extinguishes. We learned about the litmus tests, that if it's an acid (HX) that the paper will turn red, that if it's a base (MOH) that the paper will turn blue, and that if it's a neutral (MX), there will be no change. 

We also learned about the reaction types, the difference between a combination or synthesis, decomposition, single and double replacements, and finally combustion, which all are used during a daily lives, like if you take a shower using hot water that combustion is occurring. 

I like this experiment, too. I just didn't understand it the first day. I only really liked it at first, because we were still balancing equations. Once we learned about the reaction types, though, I enjoyed this even more. It's interesting that you can predict a product. 

Particle Motion

For simplicity's sake, we played with simulations on Thursday, I think. We had done quite a few of the simulations, so I'll do a brief summary on each one and basically what I learned from the experience. The first was predicting where the red particle will go among a group of blue particles and I made the reasonable guess that it would flow with the other particles, but it was far too unpredictable. Then we were told to think back to the Febreze experiment we did in class. What did the blue particles represent and what did the red one represent? Well obviously the blue was the air, because there was an abundance of them in the beginning and the red the Febreze as it flowed through the room. The next one was asking for the behaviors of molecules in a gas. Well, to put it simply, they were completely random. Their speed varied between the particles, they moved everywhere with no specific direction, and how when they collided with each other or the wall, they transferred energy, which gave them a boost of speed. However, no energy was gained during the process. Then, we were asked how temperature affects the speed of particles, which was simple enough. The hotter the temperature was the faster the particles moved, because the heat actually transferred its energy to the particles. The last experiment we were asked to complete was the difference between Helium and Krypton gas molecules. Well, watching the simulation, it was easy to see that the red particles or Helium was definitely faster than the Krypton, but if you increase the temperature for only Krypton then they would be moving at the same speed. I learned a lot through the simulations about molecules, energy transfers, temperature, etc. to say the least.

Temperature

Last week, we had done an experiment with temperature using water and alcohol. Two tubes, one of water, the other of alcohol, were placed in one of the beakers on top of some kind of heater. We were to mark the tubes of wherever the liquid reached after the thermometer increased by 10 degrees Fahrenheit each time. Immediately, we noticed that the alcohol rose faster than the water, even though they were at the same exact temperature. Later, we figured out that was because that were both composed of different substances, which increased and decreased at different speeds. That wasn't the only experiment we attempted that day. We had two beakers, one filled with cold water and the other with hot, and placed a few drops of dye in each one. The hot beaker had red food coloring and when the food coloring entered the water, everyone could see how fast the red expanded through the water and finally blended within a few minutes. That's, because the particles were moving faster and when they move faster they are able to expand at a high rate. When we placed the blue food coloring in the cold water that was refrigerated the night before, however, it slowly spread out through the water. After five minutes, it still barely even expanded unlike the red food coloring that was already fully blended. We figured this was because the cold particles moved slower. The slow the particles moved/collided, the slower it would take for a substance to combine with another. We, also, learned about the different types of thermometers, how they worked, who invented them, and if they were still used today. We learned a lot that day, though it was centered all around temperature, like how substances rise and fall at different rates, how food coloring in hot water expands faster than if it was in cold, and all about thermometers and how they're important to us.

How a Straw Works

We started with a video about two guys in Britain who decided enough was enough. No more having to walk like 6 meters to get a coke from the fridge. They were going to use a giant straw to do so which though at first didn't seem educational, ended up explaining how a straw works. Before we actually learned much about it, though we had to test this out ourselves, we were given Capri suns and told to suck it. We learned that the reason why we could suck it up was because of a vacuum like effect. When we sucked in the juice, the air inside the straw was pushing the liquid down, but when we eliminated the air, the juice could be sucked up, but there was another factor as well. The air on the outside. It pushed on the juice as well, allowing it be sucked upward when there was little air on the inside, because it was stronger. We also learned when we tried this with a giant 10 meter straw that the narrower the straw was the easier it was to suck up the liquid. We, also, learned that even if there were such thing as a perfect vacuum, the water would only reach 10.3 or somewhere around there meters before it couldn't go up any higher, because the air pressure that supported it was too weak, well not as strong as the pressure on the outside. We learned that sucking up liquid using a straw was far more complicated than we imagined.

Garbage Bag Experiment

When we first started this project, it was in the beginning of the week and we were just learning about air pressure. Our main objective was to blow up a garbage bag using straws with someone actually sitting on top then we were supposed to explain how the bag expanded. We concluded that it was because of air pressure. We learned that even though there was little air in the garbage bag to begin with, there was still pressure that forced the bag up in certain places and down in others when the air pressure outside the bag was stronger. It took a bit to fill the garbage bag with air and raise Reilly, I think that was his name, off the floor. We added more air particles into the bag and since they were warmer, they collided with each other more often, creating a greater air pressure. I guess this explains why Reilly felt the garbage bag, well the air pressure inside it, pushing him up off the ground and why the bag was able to expand. I've known that if blow air into something, in most cases balloons, then it will expand, but I guess I learned that there is air pressure that is a key factor, on the outside it presses in and on the inside it presses out, that if the pressure outside is greater it contracts, but if the pressure inside is greater it expands.