Portfolio of my Knowledge... » Chemistry

National Geographic – August 1995, Hiroshima

Fany Savina — Fri, 11 Mar 2011 18:23:07 +0000

A movie theatre, one of the very rare buildings still left partially standing so close to point of impact.

66 years ago, the very first atomic bomb was dropped by the Americans onto Hiroshima (広島市). After the a-bombing, the Americans demanded the Japanese surrender, but they still preferred death over the white flag. Then the Americans a-bombed a second city, Nagasaki (長崎市). When on my trip to Japan in 2008, we made a stop at Nagasaki, and we visited the memorial museum. It contained plenty of information about atomic bombs, the effects and post-effects of such a bombing, as well as plenty of photographs and items recovered from various victims. In the entrance was a shrine, with dozens of origami cranes stringed up. In Japanese culture, cranes signify longevity.
The bombings were both as a revenge for Pearl Harbor, a counter-attack to Japan's invasions, and as a way to intimidate other WWII enemies. The American's plans worked, as a few days after the Nagasaki assault, WWII ended completely. Although the Allies provided technical help, financial aid for reconstruction was sparse, everything went to helping rehabilitate allies in Europe. Also, many thought that the earth of Hiroshima was spoiled for ever, but when greenery started growing again, a new hope transpired. By 1953 the water and sewage systems were fully restored, and a decade later the population came to half a million people, although many people were still sick with the after effects of radiation. After a while, the bombing was seen as a way to make a fresh start. Before, Hiroshima had been the ultimate seat of militarism, its port used for dispatching various invasions. When rebuilt, the people of Hiroshima self proclaimed their new found place as the City of Peace, containing over 700 maintained parks, a towering skyline, and cosmopolitan shopping arcades.
Every year, in the Hiroshima Memorial Park, thousands gather to honour the dead, with special seats reserved for the hibakusha (bomb survivors). Also the Hiroshima Memorial Museum receives more visits from Americans and foreigners than it does from japanese schoolchildren on school trips.

That theatre still stands today as a memorial.

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Marie Curie

Fany Savina — Wed, 27 Jan 2010 17:44:16 +0000

Marie Sklodowska was born in Warsaw, Poland on the 7 of November 1867. Known as a great scientist who discovered two new elements (Polonium, Radium), she was also the first woman to receive a Nobel Prize, as well as the first person to receive two Nobels in her lifetime. At a young age she moved to Paris where she became a governess to help her sister pay her college funds, who when finished, returned the favor and she aided Marie to pay the entrance fee of the Sorbonne. There she met Pierre Curie, another fellow student interested in science. They married and later had a total of two daughters, Irene and Eve. Mary and Pierre both joined forces and studied radioactivity, from where they discovered radium. Pierre died on the rainy Thursday 19 of April, 1906 from a road accident. Marie was devastated and depressed and she sought companionship in her late husband’s best friend, Paul Langevin. Media exposed her affair and it practically destroyed her reputation and all she had achieved so far. And since she was a woman, her achievements were mostly seen as Pierre’s achievements (the man) and when he died, she was supposed to accept the government’s offer of a pension to support herself and her children. She boldly refused and took her husband's job as a professor at the Sorbonne, and she continued her researches. After the media outbreak concerning her affair, she fought hard to be respected again. Then her second Nobel was given to her and she was cast in a new light. She concentrated on finding healing powers with radioactivity and she even went to battlefields during WWI to X-ray the wounded soldiers and find the bullet fragments. She saved many lives. She set up an institute and continued her life successfully, though she would not acknowledge the fact that radium was dangerous and could cause illness. She died on July 4, 1934, in France due to exposure to radioactive substances and pure radium most of her life. Irene, her first daughter, followed in her mother's footsteps and she too received a Nobel in science, along with her husband. Eve went down the literature path and she published the first biography of Marie Curie.

Reference:

http://www.aip.org/history/curie/trag1.htm

http://en.wikipedia.org/wiki/Marie_Curie

http://en.wikipedia.org/wiki/Pierre_Curie

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Replicating a Scientific Experiment

Fany Savina — Thu, 21 Jan 2010 14:33:40 +0000

Since I was in my molecules and atoms period, I also tried doing this experiment: Measuring the Diameter of a Molecule. The experiment was found on a school website. I read the essay summarising the experiment and I thought the concept was pretty simple. It was basically filling out a rectangular straight-sided pan with water and to make sure the water bulged over the side of the pan. Then a wire rod was to be placed over the water near the middle of the pan. It had to just lightly touch the water. A single drop of oil was to be dropped into the middle of 1 section created by the rod. The oil was then to spread out over the surface of the water and when it had covered the whole surface between the side of the pan and the side of rod, the rod was to be moved another couple of inches to allow the oil to spread even more. It continued liked this until you were supposed to see the oil starting to break up and see fissures in what should look like a very thin blanket of oil over the water. As soon as this happened the rod must be left alone and the length and width of the oil blanket must be measured. The idea was that all the molecules started spreading out and just before the cracks could come, they would all be flatly the one beside the other, making the oil one molecule thick. A calculation was then given out to find out the height of these molecules. Volume=Length*Width*Height

××

Assuming the drop was 1 cubic millimetre and the oil's length was 400 mm and the width was 300 mm:

××

0.00000833mm is the supposed height of one oil molecule. If you want more details on this experiment, visit the site, but details were my exact problem.

When I tried this experiment I did everything the experiment told me to do. The thing is, it doesn't tell you a lot. A lot of variables that need to be known are not explained, for example, the type of oil, the amount of time the experiment takes, or even the water temperature. I used olive oil because it was the only oil I had. I wasn't able to reproduce this experiment even though I tried three times. The first time I used ambient temperature water and a tiny drop of oil from the tip of a needle. It didn't work. The second time I used ambient temperature water again but this time with a slightly larger drop which I think was roughly 1 cubic mm. I used a pipette for the drop this time. This time it seemed to actually spread but it spread out into a bigger drop VERY SLOWLY. I left it overnight and in the morning the drop had clung on the edge of my pan and it had broken down into several bubbles. The third time I used the same amount of oil but I used hot water. This time the drop didn't even bother spreading.

My conclusion is that I have no idea if the proposed answer they gave could be right or if it is downright wrong. If it is wrong then the experiment was probably found somewhere else and it was probably not carried out before putting it on their website. If it is right, then whoever wrote out the experiment did not do it properly because I could not carry it out due to missing details.

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Electricity

Fany Savina — Wed, 20 Jan 2010 14:57:40 +0000

Electricity is a general term for a wide range of events resulting from the presence or flow of an electric charge. These events could be things commonly known such as lightning or static electricity, but an other event possible could be electromagnetic fields. People have been aware of the shocks they received from electric fish and eels for a long time. Old Egyptian texts found named these fish as 'Thunderers of the Nile' and they were proclaimed as the 'protectors' of all fish. Later on, Ancient Greek, Roman and Arabic physicians wrote about these fish. They knew of the numbing effect of the shocks, and they knew the shocks could move with conducting objects. These electric fish were used as medicine to cure gout or headaches. The theory was that the sudden shock would shake away the sickness. Thales of Miletos made a series of observations around the year 600 BC concerning static electricity. He believed the static was because the objects he rubbed became magnetized because of friction. After him, electricity was no more than an abstract curiosity for millennia until 1600. In the early 19th century, the work became more precise and extensive experiments and observations were made. In the late 19th century, electricity was discovered and it became a tool in science and modern life instead of a scientific curiosity. People like Nikola Tesla and Thomas Edison showed up and electricity became a necessary force for the Second Industrial Revolution.

Electricity comes from atoms. The protons and neutrons create the center, the nucleus. The protons are positively charged and electrons, which rotate around the nucleus, are negatively charged. The neutrons, hence the name, are neutral. They are not charged. The actual electricity comes from when the electrons move from one atom to the other. Negatively-charged electrons are always attracted to positively-charged protons.

Some atoms are excellent at conducting because there are tracks which the electrons follow. The electrons mostly stick to the closest track to the nucleus because it requires less energy. If the track the most extended to the outside is clear enough of other electrons, the electrons can jump from one track to another and exit their previous atom to enter a new one. These atoms are Conductors. If the track isn't clear or if the atom holds on tightly to it's electrons, the electrons cannot move and no electricity is created. Another reason why some atoms conduct better than others is because of their Atomic Number. This number is written on the periodic table of the elements, and it basically tells you how many protons are in the nucleus of one atom from that element. The positively-charged protons attract negatively-charged electrons, making the passing from one atom to the other more tempting and once the electrons are moving, the attraction makes it easier for them to move.

References: http://en.wikipedia.org/wiki/Electricity,http://www.pbs.org/transistor/science/info/conductors.html,http://en.wikipedia.org/wiki/Atomic_number,http://www.pcguide.com/ref/power/ext/basicsWhat-c.html

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Molecules, Atoms and Elements

Fany Savina — Wed, 20 Jan 2010 10:52:26 +0000

An atom is the smallest piece of an element which still has the element's chemical properties. They are made up of smaller particles called protons, neutrons and electrons. The protons and neutrons bond together in the middle to form the nucleus and the electrons rotate around this nucleus in a cloud. The ratio of protons to neutrons is unique to one sort of atom. An element is lots of atoms, but they all contain the same amount of protons to neutrons. If two sorts of atoms combined, a compound would be created. Some different sorts of atoms are glad to bond together and form molecules (oxygen + chlorine), but others do not bond very well (neon + argon).

A molecule is made up of at least two atoms held together with very strong chemical bonds. These bonds are made because of the constant passing of electrons between atoms. A molecule is the smallest particle, next to atoms, in a chemical compound or element that actually has the chemical properties of that compound or element.

If you find this hard to understand, visualise a pile of paper clips which are all the same. They all have the same colour, size, and weight. If you divide your pile into two separate equal piles, and divide those piles in two, eventually, you will have one paper clip per pile. These can represent an atom. Your paperclip is still useable (i.e. it still has it's chemical properties), but if you divide even more by cutting the paper clips in half, they won't be able to actually hold paper. Now visualise a different pile of paper clips, but they are all still the same. Separate them down like the first pile and you get your atoms. Then take a paper clip from each pile and clip them in together. You have now created a molecule, i.e. two atoms joined chemically. The full pile of all the same paper clips (atoms) would represent an element.

References:http://education.jlab.org/qa/element.html,http://science.howstuffworks.com/atom1.ht, http://en.wikipedia.org/wiki/Molecul,http://whatis.techtarget.com/definition/0,,sid9_gci856651,00.html

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