Current Events 3/29/12

The article I read was about a movie director named James Cameron. He completed the first human dive in 52 years to the ocean’s deepest spot. He navigated his mini-submarine down in the western Pacific in an underwater area known as Challenger Deep. He began this dive on Sunday, March 25th at 3:15 p.m. Eastern Daylight time. Then, he landed on the bottom at 5:52 p.m. and surfaced at 10 p.m. His team planned to bait the area with food that might have become a magnet for larger creatures luring in the dark.
I believe the article was intriguing and shocking and the explanation was monumental. This was the first human dive in 52 years to the ocean’s deepest spot. Also, he took on the incredible danger of embarking on this journey alone. Another impressive thing was that the mini-submarine was his own design. This monumental expedition led James Cameron to embarking into an “alien world”.

Atoms

Lab Report: States of Matter

For the past week, in science class, we did several labs involving matter. We observed the states of matter and other aspects of matter. The main purpose of the labs was to understand the distance between chemical changes and physical changes. Through the duration of the week, other knowledge was also compiled.

The first two labs were in the same context because both involved candles. The first was quite basic. Notes were taken on the physical properties of a candle. However, no chemical properties were noted because one cannot observe matter’s chemical composure unless it is manipulated. Once the candle was lit, observations on chemical and physical properties were recorded. Physical changes were first written down. These would include that it was melting, smooth, and shiny. Now that it was lit, chemical changes included things such as the fact that it was burning. The evidence of this was shown in the flame and smoke. In addition, this lab was a source of knowledge involving combustion. Combustion is the act or process of burning. Thus combustion occurred when the candle was lit. People see combustion on a daily basis without even acknowledging it. When someone lights a candle in their kitchen or lights a birthday candle, one could say that they are performing a science experiment. This could be useful when forming hypotheses regarding combustion and burning.

 The second part of this lab involved candle but had a different purpose and procedure. A candle was set aflame first and then a mixture of vinegar and baking soda was created. This formed a gas known as carbon dioxide. This gas was poured over the candle and caused it to blow out. The carbon dioxide surrounded the air around the flame, which needs oxygen to survive, and removed the oxygen, putting out the flame. A physical change occurred when the candle was lit and it was put to a stop when the fire went out. Insight into the life and death of flames was provided and can be used on a regular basis. The air we blow out of our mouths is carbon. So, every time we blow out a candle with our mouths we are performing this experience in a different way. An understanding of the science behind blowing out candles was developed.

In the following lab, physical and chemical changes of a marshmallow were performed and identified. After notes were initially taken on the description of the marshmallow, it was ripped in half. This was a physical change because it only affected its form, not its composition. Next, a bite was taken from the marshmallow. This was done to have an initial taste. After another marshmallow was placed on a skewer, it was held over a Bunsen burner until it was burnt. The blackened part of the marshmallow was tasted. The taste of the marshmallow changed drastically. For one, instead of being sweet, chewy, and powder-like, it was smoky, creamy, and crispy. Both physical and chemical changes had taken place. A chemical change happened when the marshmallow was burnt and when the inside melted a physical change occurred. After completing the procedure, it is now clear to me that whenever we roast marshmallows, we are executing a scientific procedure involving physical and chemical changes.

The final lab involved sugar cubes. Two sugar cubes were first taken and crushed into a powder with a mortar and pestle. The sugar had been grinded and it underwent a physical change. It was then poured into a glass of water and stirred. The sugar was no longer visible and had dissolved, going through a physical change. However, the sugar was still present because the water tasted sweet. Next, two different sugar cubes were put in a test tube and were held over the Bunsen burner. Observing the contents of the test tube, it was noticed that the sugar was burning and turning black. Smoke started coming out of the tube and black crystals were formed inside the test tube. Once the test tube was taken off the flame, many other changes were noticed. The sugar was now burnt, black, and crystallized. In fact, it wasn’t sugar anymore. Once sugar underwent the chemical change of being burnt, a new substance was formed inside the test tube. This lab conveyed the significance of chemical change in such a simple substance as sugar.

Clearly, physical and chemical changes of matter can be observed in numerous ways. The above labs utilized burning and flames to entice the students to want to learn about matter, chemical changes, physical changes, and other related topics. To conclude, forming an understanding of substances and chemical changes can not only help in an experiment in a laboratory but can also add to people’s knowledge of reactions that happen throughout their lives on a daily basis.

Separating Mixtures (Procedure)

1.  Use the spoon to remove the kidney beans from the mixture.
2. Next, remove the toothpicks with the spoon.
3. Then, use the spoon to remove the bug.
4. Put the magnet in the mixture and remove the iron filings.
5. Fold the filter into a cone and put it in the funnel. Put this over the beaker and pour in the mixture. The sand is now in the funnel.
6. Put the beaker with the leftover contents of the mixture on the hot plate.
7. Once the water evaporates, the salt is visible.
8. Remove the beaker from the hot plate and turn it off. Clean up the rest of the materials.

Frog Dissection Lab

In the frog dissection lab, we cut open a preserved frog and examined organs inside it. It may have been a little gross, but it was very fascinating! Even though a frog may not seem like it is anything like a human, our organs are very similar. The main differences, in my opinion, are their location and their appearance. But that may just be because of proportions.However, this is not what we noticed right away. Our first direction was to identify whether it was a male or a female. We opened it and saw no eggs. It was concluded that the frog was a male after the testes were located. Then, we saw these small noodle-shaped structures attached to the body. These were the fat bodies. Because there were so many of these, it took awhile to take them out. Sadly, we accidently ripped out the testes when we wer dissecting. Even though these organs were small and hard to find, there were some organs that you can't miss by sight. The biggest was the liver. It was made up of three big lobes and seemed to take up alot of the space inside of a frog. It also hinders the examination of the other organs. After taking out the liver, you could see so many more organs. One organ that stuck out to me was the gallbladder. It looks like a small green bubble. It is located directly under the liver. Also, I was humored by the appearance of the heart. It actually somewhat looked like a cartoon heart! But it was a little more triangle-shaped than a cartoon heart. Also, the small instestine looked really cool when you removed it and stretched it out. It was so long! All of these organs are in our bodies also. So, when you look inside a frog, it isn't too hard to locate all of the organs. It was so amazing to be able to touch and examine each organ and remove it from the frog. Oddly, it was gross at the same time! We saw organs like the spleen, kidney, lungs, and pancreas. I would definitely do it again. But if I did do it again, I would hope that it doesn't smell as bad as the first time! For more information on frogs, you can go to these websites:
Here is an online dissection game:
http://www.surgery-games.org/43/Dissect-a-Frog.html
Note: This game is online dissection in which you then have to identify the individual parts.
For further knowledge about frogs, visit this website:
http://www.e-tutor.com/et3/lessons/view/52133/print         
Diagram of the internal structure of a frog:
 

Chicken Wing Dissection

Recently, my science class dissected a chicken wing to study the different types of tissue in organisms. Though we may seem like completely different species, we all have the same basic tissues in our arms. For example, we both have biceps and triceps, the muscles that control the movement of the arm, or wing. Also, we both have skin, tendons, ligaments, and nerves. In addition, when all of these tissues had been removed, you can see that both the chicken and and the human have an ulna, radius, and humerus. These are the bones of the arm. I know some people might have thought this was disgusting, but it is the food we consume in our bodies and I found the dissection quite helpful in learning about our bodies. This is because our build and a chicken's build are quite similar to each other.

Diffusion Lab Report

The diffusion lab created an understanding of the processes inside a cell using iodine, cornstarch and water. The purpose of the lab was to observe the diffusion of a substance across a semi permeable membrane.  To do this, iodine was used as the indicator and a plastic baggie was used as the permeable membrane that separated it from the substance it indicated which in this case was starch. Since iodine is an indicator for starch, the predicted outcome was that when osmosis, a specified form of diffusion with water, occurred and the iodine moved across the membrane, it would change color in the presence of starch.  Initially, the iodine was hypertonic since it was highly concentrated in the beaker. As it moves across the permeable membrane, it would be diluted to a lower concentration by the water and became hypotonic. It was predicted that the iodine would diffuse across the permeable membrane so that the concentration of iodine in both the baggie and the beaker would be the same and thus isotonic.

After 15 minutes of observation, the solution in the baggie changed from white to a shade of purple while the solution in the beaker remained orange. This leads to the conclusion that the iodine diffused through the baggie and underwent the process of osmosis, as predicted, to indicate the starch by changing its color. Since the contents of the beaker remained unchanged, it was apparent that the semi permeable membrane did not allow the starch to transfer from the baggie to the beaker thus the baggie was selectively permeable. The occurrences in this lab mimic the behavior of the cell membrane. The cell membrane is what protects the cell and selectively controls the movement of molecules into and out of the cell. Thus, it is selectively permeable just as the baggie was selective with the iodine and the starch.  This is how cell membranes react with water and food molecules. Certain molecules can pass through the cell membrane to benefit the cell whereas harmful molecules are blocked from entering the cell. This process is required for the cell to function.

Looking outside of this experiment, diffusion is utilized on a daily basis by most people. For example, when a tea bag is placed in boiling water, the molecules of the tea leaves diffuse through the tea bag to color and flavor the water. Another situation where molecules are diffused by osmosis is sugar and coffee. When sugar is dissolved in coffee, the sugar molecules spread throughout the coffee and sweeten its taste. Not all diffusion is beneficial. In the case of cigarette smoke, it diffuses into the air and causes second hand smoke inhalation. Also, car and truck emissions of carbon monoxide can be deadly when diffused in high concentrations. That is why the automobile engines cannot be started inside a closed area such as a garage. These examples show how diffusion has both a positive and negative effect on the human population.