Afunugo,+Crystal

Crystal Afunugo Honors Chemistry 4th Period

Another One-Atom-Thick-Material I read the article titled, “Another One-Atom-Thick-Material.” This article was very interesting. I cannot believe that there is a material capable of existing as a free standing one atom thick film! I have never heard of graphene but now I know that graphene can be formed when you separate it from graphite. By reading this article I became a bit interested about boron nitride so I did some research on it. It was stated that in the article that boron nitride could be peeled from crystals of h-BN with adhesive tape. Was it the regular store bought adhesive tape? In the article I read that separating graphene from graphite was easy to do. That’s surprising because it seems like such a complex procedure. I also read that the method of separating objects with adhesive tape was a method also used with separating atom-thick sheets of graphene. I found it amazing that there was a picture of the boron nitride, it had a triangular shape. What makes them form that way? Why can’t the boron nitride samples have a square or circle shape instead? I also wondered if this was applied research or basic research. When the scientists’ chose to research this topic, were they looking to solve any problems or was it just to further their knowledge?

Crystal, This is amazing! You have posed many interesting questions and prized a great deal of information from this article. Wow! 5 huge stars! MW

Crystal Afunugo Honors Chemistry 4th Period

Redefining the Kilogram I read the article titled, “Redefining the Kilogram.” My first point was how I thought it was odd that the official kilogram is at Gaithersburg, MD. This is because here in the US we do not use Kilograms. We usually calculate mass in pounds! I wondered why the home of the Kilogram is here, in the USA when we don’t even use the metric system of measurement! My second point was that I didn’t know that candela was one of the seven basic units of the International System of Units!! I have never heard the term used as commonly as the other basic units such as, meter, second, mole and even ampere! If a room is dim would it be proper to say that the room is lacking candela? My Third point was that I learnt that Avogadro’s constant was defined as, “exactly the number of atoms in 12g (1 mole) of 12 C.” My most valuable point (MVP) was that I wondered how the kilogram lost some of its mass. I understand that an object losing mass it is something that occurs over a long period of time and in small amounts such as atoms. But I want to know what causes those atoms to detach themselves. If the Kilogram is locked in a safety vault there should be no change, right?

Crystal,

Amazing insights and questions. It turns out that the pound is actually defined in terms of the kilogram so we do actually use it. Great job!! 5 huge stars! MW

Crystal Afunugo Honors Chemistry 4th Period

Crude Oil Video Crude oil is found in the earths crust. I learnt by watching the video that hydrocarbons are separated by fractional distillation. The steps for the fractional distillation of crude oil begin when the oil is heated at 40 degree’s Celsius. The hydrocarbons that boil at 40 degrees Celsius turn into to vapor then condense in a long tube as it travels and collects into the other test tube. Is it normal for crude oil to have different hydrocarbons in it that boil at different temperatures? I actually find that strange because when water boils at 100 degrees celsius all of the water turns into vapor. There isn't different parts in water that have different boiling parts. So why is it that crude oil boils at different temperatures?

Crystal, Pure water boils at 100oC because it is a single compound. Crude oil is a mixture of hundreds if not thousands of compounds so these seperate out at different temperatures. Good thoughts 5 stars. MW

Crystal Afunugo Honors Chemistry 4th Period

Motion Detectors In the article, “Motion Detectors” I read about how the motion detector works. There are 3 methods that were mentioned in the article. The method of motion detecting that was most interesting to me was the echo method. The echo method works when the device sends out pulses and uses sensors to monitor the reflection pattern but when an object passes through the pulses, the reflection pattern that gets sent back is different and it detects the difference. I thought it was interesting because I’m familiar with the way bats hunt at night so I know that they use a method similar to this one. If anyone were to ask me to tell him or her one way that motion detectors work, I would definitely explain with a method that is similar to the echo method. I did not know that the light that is passing through our eyes is due to light pushing around electrons in a cis-retinal molecule. So that means the fact that we can see is due to electrons. Well, what about the protons or neutrons? All of them make up an atom. The electrons themselves cannot just push away…or can they?

Crystal, Good post but be clear on 3 things you knew and 3 things you learned. BTW bats use sound waves to detect objects - not light. MW

Crystal Afunugo Honors Chemistry 4th Period

Where Do Chemical Elements Come From The first 26 elements disseminated from the supernova star. Nucleosynthesis occurs and new elements are created. The spectroscope is used to detect chemicals inside stars.

Crystal, Well done! 5 stars. MW

Sugar; An Unusual Explosion As I read the article "Sugar an Unusual Explosion" I came across many familiar phrases like combustion, a type of chemical reaction we covered in class. The author described the quantities of the products in the chemical reaction as 23 moles of gas etc. Hmm, that word "mole" sounds familiar! Might it be Avogadro’s number; 6.02x10^23? I recall many experiments in which Mr. Williams was grinding a solid like sugar to create more surface area. I did not know that with the right surface area and oxygen something as common as sugar, wood or metal could explode and cause such destruction!

Crystal, Funny! Good job! 5 stars! BTW I like the way you set up your page. MW Oh, Thanks! -Crystal

Helium Recently, I read an article about helium balloons and buoyant forces. I learned many new facts about gases. In class we are learning about gases and atmospheric pressure. Those topics are also found in this article. I learned a new fact about myself. My real weigh is not exactly what I thought it was because of the buoyant force coming from the surrounding air making me a bit lighter then my true weight. To find my true weight I would have to weight myself in a vacuum, interesting. I always knew a helium balloon had mass but, I never understood how it could be measured, because, if it was ever placed on a scale, the balloon would just float away. At times the thought of helium having a negative mass has crossed my mind. In the article it did state however that helium does have a negative apparent weight. It has been known that the air pressure on the top of Mount Everest is 70% lower than it is at sea level. This is also true for the air at the top of room compared to the air closer to the floor or a room but to a much smaller extent. The main idea of this article was to introduce us to, Archimedes principal; The buoyant force equals the weight of the fluid/air displaced. That is my most important/valuable point

Crystal, Well done! Good summary and relevance to class! 5 stars. MW