Unit 10 Blog

1) Planck's Hypothesis says energy is released or absorbed in small packets, called photons. This theory helped Bohr create his model of the atom because there must be specific energy levels and specific paths for the electrons to travel on, due to these photons. Personally, this is the hardest concept to understand all unit because the photons could be seen as energy and particles at the same time.

2) The Plum Pudding Model included a wispy, positively charged nucleus with mobile electrons. However, this couldn’t be right because in the Gold Foil Experiment when the small positively charged particles were shot at the piece of gold foil, they usually went straight through although sometimes went slightly off course and rarely straight back to where they came from.
Rutherford’s model included the atom being made up of mostly space with a very small, positively charged nucleus and still including the electrons.

Using Planck’s hypothesis, Bohr created his new model that still had a small, positively charged nucleus, however this time he included electrons that had specific paths and energy levels.

His model was discarded because of Heisenberg’s Uncertainty Principle that stated it is impossible to know the position and speed of an object at the same time.

The Quantum Model is very similar to our modern day model, with a small, positively charged nucleus, as well as electrons that move around the nucleus in energy-specific orbitals (a region of space with a high probability of finding an electron). The only change made to this model was when protons and neutrons were discovered. They are both subatomic particles that make up the nucleus with a mass of about 1 amu, with the neutrons having no charge and the protons having a charge of +1.

I think it is cool how we made it from the Plum Pudding Model to the modern day model because they are so different, but there was only one small change made each time. It was a long process, but so are a lot of other science discoveries.

3) All of these examples of spectroscopy were caused by electrons getting excited after gaining energy, then releasing this energy in the form of light. Not all the colors are shown because each element has a different number of electrons at different energy levels, which represents different colors and frequencies. Before this unit, I knew that light was made up of waves, however I didn’t know that the electrons in the atom was actually what caused this light and colors.

Quarter 3 Reflection Blog

The first activity this week was the Molecular Model Activity packet. We learned how chemical equations are written, and focused on having the same numbers of each kind of atoms on both sides of the equations. For example, If we started with 4 Hydrogen atoms and 2 Oxygen atoms on the left side (the reactants) then we had to have exactly 4 Hydrogen atoms and 2 Oxygen atoms on the right side with the products. When we started, I knew that the equations had to be balanced, but I never understood why.

Just like the molecular model activity, this picture shows
that there are 2 O2 molecules needed to form the products. 

Next we worked on balancing equations. Before we could do this, we had to remember how to write molecular formulas correctly based off of the name. In order to balance equations we could only add coefficients in front of each compound; we can't adjust the subscripts. Then after some practice we learned some hints to make balancing the more complex formulas easier. The first hint we learned was to always adjust the coefficients of a single species last. This means if you have a single element such as Mg or O2, balance that atom last. This way, when you add a coefficient you are only changing the number of that element and not adding more of any other element/molecule. The second hint was "sometimes the temporary use of a faction or decimal is useful." This helps especially when you only need half of one compound. Then after everything is balanced, multiple by 2 throughout the whole equation to end up with whole numbers. The last hint was to balance polyatomic ions as units if they are on both sides of the equation, such as PO3, SO3, or NH4. With all of these hints, they help to balance equations without having to physically see the molecules like the first activity we completed.

The last activity we did was our Reaction completion lab. We had to try to figure out what the products were in our reactions based off of observations and tests such as splint tests and litmus papers. 

These concepts make sense to me, especially after the different activities. I think the molecular model activity helped the most to understand why and how we balance equations. The different sides of the arrow should be equal because that's how the reactions occur in nature due to the Law of Conservation of Mass.

Anesthesia

The main difference between local and general anesthetics is how much area of the body is affected. Local anesthetics only affect one part of the body such as your skin, teeth and gums, or even the spinal cord. General anesthetics affect the whole body.

There is a difference between a loss of consciousness from a general anesthetics and a deep sleep, although they are similar. In a dream, the brain forms dreams and processes information. However, the loss of consciousness does not create dreams, or even store memories.

An anesthetic is called an inhalant when it is administered through the lungs.

Nitrous oxide can cause the lungs to collapse and lower oxygen levels in tissues, so it is not used as much anymore as in the past.

Diethyl ether isn't used as much anymore either because it is very flammable, especially in the presents of oxygen, and was a fire hazard during surgeries.

Anesthetics work by preventing the nerve's communication to the brain. When this connection is interrupted, no pain can be felt. They prevent the sodium ions from getting from one nerve to the next.

Reflection Blog

     On Monday during the "Blow up Kid" activity, we learned that the reason the bag inflates is because of air pressure. We also learned how to show this on particle diagram. Before that class period I didn't realize that air pressure played a role, and I would have assumed it was just the space the air took up when moved inside the bag.

     On Tuesday, we took a closer look into how a straw works. The straw works when you draw on it and remove the air, creating a vacuum and eliminated air pressure coming from the top of the juice in the straw. The air pressure remains pushing on the juice in the pouch, and therefore pushes it up the straw and into your mouth. Now, I understand how this works after all the particle diagrams and group discussions. 

     On Wednesday during the longest straw activity, we were testing how long of a straw is possible, and that scientist use similar ideas to measure air pressure, connecting to the manometer notes we took later on. From the straw activity, I took away that there is a limit on air pressure, and that a straw can't go on forever.

     We also took notes on the different measurement units of air pressure. We learned about millimeters of mercury (mmHg), kiloPascals (kPa), and Atmospheres (atm). They can be converted back and forth using proportions like we used earlier this year. I need to work on remembering the different equivalents of the units.

     When we were taking notes on Manometers on Wednesday, it tied all the ideas we learned so far together. Reading a manometer is different if it is closed or open. When it is closed, the gas pressure is just the difference in height of the two sides of the mercury. If it is open, you have to add or subtract the difference to the air pressure depending on if the air pressure or gas pressure is lower or higher. For me it is hard to remember to look if the manometer is open or closed before starting the problem or reading the measurement. 

Archimedes Reading Articles

Archimedes went through all 5 steps in the scientific method. He asked a question; he wondered if there was a way to tell if the crown is pure gold without knowing the volume. Then, he went through the background knowledge he knew; gold is the densest medal known at that time. He also realized in the bathtub that whatever volume he put in the water, that's how much water flows out. This was an important realization for his experiment. 

Next, he formed a hypothesis. Although the article doesn't say exactly what it is, I think he would have predicted that the crown was not pure gold. When he tests the hypothesis, he put a block of gold of the same mass as the crown in a bucket full of water and let it slowly overflow. He said that if the crown has the same volume, the water level would reach the top of the bucket. However, if the crown has a larger volume, more water would spill out.

In his conclusion, he found that the crown had a bigger volume to make up for the mass lost, due to the smaller density in some of the metal used. He then reported to the kind that the crown was not 100% gold.