PlanetPapers.com RSS Feed

Analysis of Cola Lab

2017-10-31T08:55:01.937-04:00

WINE

2005-12-01T04:54:39-05:00

A Brief History of Wine "Pinot needs constant care and attention, it can't thrive if neglected.” (Film Sideways) ‘Wine is an alcoholic beverage that is made by fermenting grapes or grape juice. Wine-like beverages can also be made from other fruits or from flowers, grains, and even honey.’ (Wikipedia.org encyclopedia online) Wine, has been firmly established at the heart of civilization since ancient times. Wine is thought to have it’s origins in the Caucasus Mountains of Georgia. Among the first cultures to cultivate wine was the Egyptians, Greeks and Europeans. In ancient Egypt, wine played an important part in ceremonial life. ‘The ancient Greeks drank to the God Dionysus, in order to forgot about there worries a tradition they inherited by the Romans, who drank to their god Bacchus.’ (Wines of the World. Susan Keevil. Pg.15). Wine, has been and is an important drink in religion. In Christianity for example, wine symbolizes Christ’s blood. The representation of wine as blood has Greek origins, pre-dating Christianity. Wine, as a blessing is part of the Jewish ritual. One of Christ’s great miracles was turning water into wine at a wedding. (A great host indeed.) In the 16th century, Europeans set out into the new world, there culture which included religion and their wines helped influenced other Countries to embrace this magical drink. Being clean and safer to drink than water, wine was consumed to great amounts. In France, a bottle of wine can be cheaper than a bottle of spring water even in modern times. ‘At the end of the 20th century the world had over 8 million hectares under vine and was producing nearly 300 million hectoliters of wine. Wine now, is now made virtually all over the world.’ (Wines of the World. Susan Keevil. Pg.10). However with that being said results may vary. Wine experts consider the best tasting wines, is from countries such as France, Italy and Spain. One of the worst tasting wines I ever tasted was wine from Bolivia in South America, the taste was too sweet. This may have to do with how wine is cultivated, and how the weather and climate affect the grapes in the vineyard. Now we drink wine to Gods and Devils, The

Oxygen

2005-03-01T23:46:28-05:00

Atomic Number: 8 Atomic Radius: 66 pm Atomic Symbol: O Melting Point: -218.79 ºC Atomic Weight: 15.9994 Boiling Point: -182.95 ºC Electron Configuration: [He]2s22p4 Oxidation States: -2 History (Gr. oxys: acid, and genes: forming) For many centuries, workers occasionally realized air was composed of more than one component. The behavior of oxygen and nitrogen as components of air led to the advancement of the phlogiston theory of combustion, which captured the minds of chemists for a century. Oxygen was prepared by several workers, including Bayen and Borch, but they did not know how to collect it, did not study its properties, and did not recognize it as an elementary substance. Priestley is generally credited with its discovery, although Scheele also discovered it independently. Its atomic weight was used as a standard of comparison for each of the other elements until 1961 when the International Union of Pure and Applied Chemistry adopted carbon 12 as the new basis. Sources Oxygen is the third most abundant element found in the sun, and it plays a part in the carbon-nitrogen cycle, the process once thought to give the sun and stars their energy. Oxygen under excited conditions is responsible for the bright red and yellow-green colors of the Aurora Borealis. A gaseous element, oxygen forms 21% of the atmosphere by volume and is obtained by liquefaction and fractional distillation. The atmosphere of Mars contains about 0.15% oxygen. The element and its compounds make up 49.2%, by weight, of the earth's crust. About two thirds of the human body and nine tenths of water is oxygen. In the laboratory it can be prepared by the electrolysis of water or by heating potassium chlorate with manganese dioxide as a catalyst. Properties The gas is colorless, odorless, and tasteless. The liquid and solid forms are a pale blue color and are strongly paramagnetic. Forms Ozone (O3), a highly active compound, is formed by the action of an electrical discharge or ultraviolet light on oxygen. Ozone's presence in the atmosphere (amounting to the equivalent of a layer 3 mm thick under ordinary pressures and temperatures) helps prevent harmful ultraviolet rays of the sun from reaching the earth's surface. Pollutants in the atmosphere may have a detrimental effect on this ozone layer. Ozone is toxic and exposure should not exceed 0.2 mg/m# (8-hour time-weighted average - 40-hour

Avogadros Number

2004-11-28T23:21:31-05:00

Avogadros number is the number 6.0221367 x 10^23, commonly rounded to just three significant digits: 6.02 x 10^23, and is the number of representative particles in a mole. Avogadro’s number is commonly used to compute the quantities of substances involved in chemical reactions, called stoichiometry, and is one of the most important and versatile components of modern chemistry. Avogadro’s number is named after the Italian physicist Amadeo Avogadro. Avogadro’s number first came about when Amadeo Avogadro proposed Avogadro’s law in 1811. Avogadro’s law states that under the same conditions of temperature and pressure, equal volumes of different gases contain an equal amount of molecules. The specific number of molecules in one gram-mole of a substance is the value 6.02 x 10^23. For example, the molecular weight of oxygen is 32, so one gram-mole of oxygen has a mass of 32 grams and contains 6.02 x 10^23 molecules (Blauch). Avogadro’s number also deals with the mole. The mole is a SI unit used to measure the amount of a substance, and is equal to Avogadro’s number. It is equal to the number of carbon atoms in exactly 12 grams of carbon-12. A mole of any substance contains 6.022127 x 10^23 representative particles. A representative particle is any type of particle, such as atoms, molecules, formula units, electrons or ions, and 1 mole of any substance always contains the same number of molecules. Avogadro’s number relates the mass of a mole of a substance to the mass of a single molecule. For example, to find the mass of one molecule of H2O, you would use the formula: ( Mass ) / (Avogadro’s number ) Since the molecular mass of H2O is 18, then to formula would be: ( 18g ) / ( 6.02 x 10^23 ) By using this formula you discover that the mass of one molecule 2.99 x 10^-23 grams (Dickson 106). A major use of the mole is stoichiometry. The word ‘stoichiometry’ derives from two Greek words: stoicheion (meaning "element") and metron (meaning "measure"). Stoichiometry deals with calculations of the masses of reactants and products in a chemical reaction, and is a very mathematical part of chemistry. You can use stoichiometry

Two Main Radioisotopes in Medicine

2004-11-10T02:00:51-05:00

Determining pH of identical strong and weak solutions

2004-03-16T04:30:00-04:00

Experiment: Determining pH of identical strong and weak solutions Date: 31/10/03 Aim: Plan and perform a first-hand investigation to measure the pH of identical concentrations of strong and weak acids. Equipment: · Deionised water (H2O) · Tartaric Acid (C4H6O6) · Citric Acid (C6H8O7) · Sulfuric Acid (H2SO4) · Acetic Acid (CH3COOH) · Hydrochloric Acid (HCl) · Ammonium Chloride (NH4Cl) · Tap Water (H2O) · Nitric Acid (HNO3) · Probe · Ferric chloride (FeCl3) · Wash bottle · Sodium Chloride in tap water (NaCl) · Beakers · Sodium Chloride in deionised water (NaCl) · Data logger Method: 1) Make sure there is an equal molarity of each substance. In this case 0.1 moles/litre. Therefore there are 0.1 moles of each substance in solution. 2) Place each of the substances in a beaker. 3) Calibrate the data logger by using buffer zones of pH 4 and 10. 4) Place the probe into one beaker and click the start button on the data logger. Record the pH level of the substance. 5) Remove the probe and wash thoroughly using the wash bottle. 6) Repeat for all the other substances and record their pH’s. 7) Determine which solutions are strong and which are weak. Results: Substance pH Acidic, Basic or Neutral Strong or Weak Citric Acid (C6H8O7) 2.4 Acidic Weak Acetic Acid (CH3COOH) 3.0 Acidic Weak Tartaric Acid (C4H6O6) 2.3 Acidic Weak Nitric Acid (HNO3) 1.5 Acidic Strong Hydrochloric Acid (HCl) 1.5 Acidic Strong Sulfuric Acid (H2SO4) 1.4 Acidic Strong Ferric chloride (FeCl3) 1.5 Acidic Strong Ammonium Chloride (NH4Cl) 7.0 Neutral - Sodium Chloride in deionised water (NaCl) 5.6 Acidic Very Weak Sodium Chloride in tap water (NaCl) 7.2 Neutral - Deionised water (H2O) 6.0 Neutral - Tap Water (H2O) 7.0 Neutral - Discussion: By observing our results it can be seen that even though all solutions have the same concentration they can still be strong or week. It can be seen that all organic acids eg. Acetic acid, Citric acid and Tartaric acid are all weak acids whereas all inorganic acids such as Sulfuric acid, Nitric acid and Hydrochloric acids were strong. It was also discovered that ionic molecules could be acidic eg. Ferric Chloride. In the past it has been said that all ionic substances tend to be more neutral than acidic or basic. This has all been changed now and we have the Brønsted Lowry concept. With the Brønsted-Lowry concept we usually refer to a hydrogen ion as a proton. That is because a proton is all that is left when a hydrogen atom loses an electron to become an ion. Brønsted and Lowry independently came up with the idea that an acid is an acid because it provides or donates a proton to something else. When an acid reacts, the proton is transferred from one chemical to another. Note that in order for an acid to act like an acid, there needs to be something for it to react with. There needs to be something to take

Rate of Reaction

2004-01-12T00:59:54-05:00

Rate of Reaction December 17, 2003 Rate of Reaction-Report The purpose of this lab was to find the rate of reaction. I watched to see how fast Alka-Seltzer would react with different liquids. I changed the type of liquid from water to vinegar for some of the experiments. I also used one tablet that was solid and one that I had crushed up to see the differences. I changed the temperature with each new experiment, except when I was comparing and contrasting solid to ground up tablets. I always used the same amount of liquid also. The tablet that was ground up always dissolved quicker than the solid tablet in the same temperature. This is because of molecular collisions. The solid tablet could only make contact with the liquid on the surface, causing the reaction to always occur from the outside to the inside, which made the reaction take longer. The ground up tablet could make contact with the liquid all through the powder, causing more molecular collisions in the same amount of time. I also noticed the hotter the liquid was the faster the reaction time was. This is because there is more energy in the water and the molecules are colliding faster causing the reaction to speed up. From my results I predicted that a solid tablet, in water, would react in 73.9 seconds at 13°C. I also predicted that a ground up tablet would react in 43.3 seconds at 13°C. I made my predictions by looking at the average reaction time from my labs, and calculating the average reaction speed. The solid tablets reaction speed was about 3.61 seconds per degree. While the ground up tablets reaction speed was about 1.67 seconds per degree. After I found the speed of the reaction, I multiplied the average reaction speed by the temperature I was trying to predict. In my results both the solid and the ground up tablets dissolved faster in water than in vinegar. I personally thought that the tablets would actually dissolve faster in vinegar.Type of Liquid Amount of Liquid(mL) Temperature of Liquid (°C) Consistency of Tablet Time of

Sarin Gas and other Nerve Agents

2002-11-09T13:00:00-05:00

The arms race has always been occurring, as people endlessly compete to have more power and better weapons. This century great leaps in technology have been made, explosives and bombs have been the main weapon of development. However the problem with bombs is that they destroy everything they hit, not only do they destroy the designated target but also everything else around it. This renders the land and buildings in the hit zone useless, and causes more damage than is necessary. This problem especially arises when the targets are human, and you only want to destroy them. The answer to this problem was biological and chemical weapons. Lethal gases such as Sarin gas are used throughout the world in a new age of biological and chemical warfare. Though illegal they are still being used in terrorist attacks and wars today. These weapons are more commonly known in the scientific world as nerve agents or nerve gases of which there are over 2000 varieties, but they are only one type of chemical warfare. They were discovered completely by accident in 1930 by a chemist called Dr. Gerhard Schrader who worked for a company called “IG Farben”, he discovered nerve agents while trying to create a more effective insecticide. What he came across was Tabun, an enormously toxic organophosphate compound. Organophosphates kill insects and humans by jamming the nervous system, which is why he was using it to try and develop an insecticide. After two more years of development he created an even stronger gas Sarin.

History

Looking back over the centuries, it seems chemical warfare has been in use ever since fighting between people started. The first recorded evidence of chemical weapons was in 400bc, when Spartan Greeks used Sulphur fumes against enemy soldiers. Sulphur was not very efficient and rarely killed, but often disorientated or knocked out the victim(s). Gradually over the year’s chemical warfare developed, from the early use of poisons like cyanide for assassinations to the invention of nerve gases such as Sarin. The first real use of nerve agents was during World war one on April 22, 1915. During the battle of Ypres, the Germans utilised nerve agents for the first time ever for war purposes. They unleashed a deadly new gas called “chlorine gas”(CL2) on the British and French in a trail run. It was estimated that this new blistering agent cost over 5000 lives. In retaliation to

Chromium - research

2002-10-05T14:00:00-04:00

Chromium was discovered by Louis – Nicholas Vauquelin in France, 1797 and prepared the metal itself the following year. The name Chromium originated from the Greek word “chroma” meaning “color”, named for

Hydrogen

2001-10-24T14:00:00-04:00

Background An example of a gas would be hydrogen. A chemical property is how a substance changes its identity. An example of this would be being able to support flammability. A physical property distinguises one type of matter from another and can be observed without changing its identity. An example of this is something’s boiling point because when you change a liquid to a gas it does not change its identity only its form. A chemical change is when something changes identity and example of this would be burning something because you are changing the substances identity. An example of a physical change would be chopping wood because it is still wood just in pieces. An exothermic reaction is when something lets off heat to make a change. An example of an exothermic reaction is turning water to ice because the water needs to cool down and let off energy to exist as a solid and that is why ice cubes are cold. An endothermic reaction is when a substance needs to gain heat and takes it in. An example of this would be water turning into gas because gas needs a lot of energy and that is why when you apply heat to water it turns into a gas. Purpose To determine the properties of the gas, hydrogen, by generating the gas though a chemical change and identifying the gas by performing a simple test. Hypothesis For my hypothesis, I think that the burning splint will react by making the flame get slightly bigger. I think that hydrogen is less dense than air is. Materials

vinegar

Mg. Ribbon

goggles

test tube

wooden splint.

lighter Procedure First thing, we had to obtain the vinegar and make cualitative observations about it and do the same with the Mg ribbon. Then we had to roll the Mg ribbon into a ball and it to the vinegar. After adding the Mg ribbon, we had to quickly put our thumb over the vial and make observations of what was happing during the reaction. After waiting four minuets. After that, we had to light a wooden splint on fire. I took my thumb off the test tube and applied the burning splint. Then observed about the reaction. Conclusion For my hypothesis, I was partly correct about what would happen when the burning splint was applied to the vial because the flame did grow larger but it also made a noise as well. I was correct about saying that it

Hydrogen Peroxide

2000-12-13T13:00:00-05:00

(H2O2), a colourless liquid usually produced as aqueous solutions of various strengths, used principally for bleaching cotton and other textiles and wood pulp, in the manufacture of other chemicals, as a rocket propellant, and for cosmetic and medicinal purposes. Solutions containing more than about 8 percent hydrogen peroxide are corrosive to the skin. First recognized as a chemical compound in 1818, hydrogen peroxide is the simplest member of the class of s. Of the several processes of manufacture, the principal ones involve reactions of oxygen from the air with certain organic compounds, especially anthraquinone or isopropyl alcohol. Major commercial grades are aqueous solutions containing 35, 50, 70, or 90 percent hydrogen peroxide and small amounts of stabilizers (often tin salts and phosphates) to suppress decomposition. Hydrogen peroxide decomposes into water and oxygen upon heating or in the presence of numerous substances, particularly salts of such metals as iron, copper, manganese, nickel, or chromium. It combines with many compounds to form crystalline solids useful as mild oxidizing agents; the best-known of these is sodium perborate (NaBO2H2O23H2O or NaBO34H2O). With certain organic compounds, hydrogen peroxide reacts to form hydroperoxides or peroxides, several of which are used to initiate polymerization reactions. In most of its reactions, hydrogen peroxide oxidizes other substances, although it is itself oxidized by a few compounds, such as potassium permanganate. Pure hydrogen peroxide freezes at -0.43º C (+31.3º F) and boils at 150.2º C (302º F); it is denser than water and is soluble in it in all proportions. The most important covalent peroxide is hydrogen peroxide, H2O2. When pure, this syrupy, viscous liquid has a pale blue colour, although it appears almost colourless. Many of its physical properties resemble those of water. It has a larger liquid range than water, melting at -0.43º C and boiling at 150.2º C, and it has a higher density (1.44 grams per cubic centimetre at 25º C) than water. The dielectric constant of pure H2O2 is, like that of water, quite high--70.7 at 25º C compared with a value of 78.4 for water at 25º C. However, adding water, which is miscible in all proportions, causes the dielectric constant to increase to a maximum value of 121 at about 35 percent H2O2 and 65 percent H2O. World production of H2O2 is well over one-half million tons per year, making it a major industrial chemical. Most industrial hydrogen peroxide is prepared by a well-conceived process introduced

The Element Iron

2000-12-10T13:00:00-05:00

Iron comes from the Latin word ferrum. From ferrum its symbol became Fe. The atomic number of iron is 26, and its atomic weight is 55.845. Iron is a magnetic, bendable, shiny white metallic element. Pure iron has a hardness that ranges from 4 to 5. It is soft and ductile. Iron

The Debate Over the Use of Natural vs. Synthetic Vitamins

2000-11-25T13:00:00-05:00

One clear representation, which will be discussed later, of the controversy surrounding the use of synthetic products versus natural products, lies in vitamins. A vitamin is a composite of the natural world that is made up of enzymes, coenzymes, antioxidants, and mineral activators. The decision on which one a person would choose usually comes down to cost, confusion, and/or common assumptions. The arguments about synthetic versus natural can easily be decided with a little bit of knowledge.

Concentration and Reaction Rate

2000-10-11T14:00:00-04:00

How concentration affects reaction rate. The aim of this investigation is to see how the concentration of a reactant in ratio to the reactor affects the rate of a reaction. When hydrochloric acid and Thiosulphate react together sulphur is liberated this means that as the reaction goes on the solution will become yellow and will change from being transparent to translucent to opaque. The sulphur is formed as a solid but not in the usual precipitation way. Na2 + S2 + 2HCL 2NaCl+SO2 + S2 +H2O To time the reaction I will draw a black cross on a piece of plain paper on which the beaker of reactants will be placed (HCL and Thiosulphate). When the chemicals come into contact with each other I will start timing with a stopwatch and will stop timing when the cross is longer visible through the beaker from above. A reaction: A chemical reaction between to chemicals can only happen if their molecules can collide into each other. Out of many collisions there will be a few successful collisions, which means that the two molecules will exchange electrons and that means that they have reacted. These molecules have to hit each other in the right direction and at the right speed; in short the rules for a “successful collision” are specific and complex. But if the number of collisions per second increase so will the number of successful collisions increase. This means that the rate of the reaction has increased. For a reaction to occur you also need the required activation energy which means that if there isn’t enough the reaction won’t take place although catalysts can lower this. Input Variables: Catalyst Concentration of acid or thiosulphate Temperature Light Temperature: If you increase the amount of energy in a group of molecules the reaction rate will increase. When you give energy to molecules they tend to move about a bit more. And this means that if they are moving rapidly from place to place they are going to have a lot more collisions and because they are having lots of collisions the chances are that they will have a successful collision a lot more quickly than if they weren’t. This basically means that reaction rate is increased as temperature increases. I believe that temperature is directly proportional

Arthur Kornberg

2000-08-15T14:00:00-04:00

A. Personal Information Arthur Kornberg (1918-), American biochemist and physician, claims he has never met “a dull enzyme.” He has devoted his life to pursuing and purifying these critical protein molecules. His love of science did not spring from a family history rooted in science. He was born on March 3rd, 1918, the son of a sewing machine operator in the sweatshops of the Lower East Side of New York City. His parents, Joseph Aaron Kornberg and Lena Rachel Katz, were immigrant Jews who made great sacrifices to ensure the safety of their family. They had fled Poland, for if they had stayed, they would have been murdered in a German concentration camp. His grandfather had abandoned the paternal family name Queller, of Spanish origin. This was done to escape the fate of the army draft; he had taken the name of Kornberg, a man who had already done his service. His father used their meager earnings to bring and settle his family in New York City and was thrust into the sweatshops as a sewing machine operator. He, along with his brother Martin, 13 years older and sister Ella, nine years older, was encouraged by loving parents to obtain a good education. The public school reinforced this ideal. Education was the road of opportunity for social and economic mobility out of the sweatshops. His early education in grade school and Abraham Lincoln High School in Brooklyn was distinguished only by his “skipping ” several grades. There was nothing inspirational about his courses except the teachers’ encouragement to get good grades. When he received a grade of 100 in the New York State Regents Examination, his chemistry teacher glowed with pride. It was the first time in over twenty years of teaching that a student of his had gotten a perfect grade. Arthur was a brilliant student who graduated from high school at the age of fifteen. He enrolled in City College in uptown Manhattan. Competition among a large body of bright and highly motivated students was fierce in all subjects. His high school interest in chemistry carried over into college. After receiving his B.S. degree in biology and chemistry in 1937, and since City College offered no graduate studies or research laboratories at that time, he became one of two hundred pre-med students at the University of Rochester. All through college he worked as a salesman in his parents’ furnishing store,

Genetically Engineered Food

2000-05-03T14:00:00-04:00

Millions of people all over the planet suffer from poverty and starvation. One very interesting but experimental solution to the problem of world hunger is genetically engineered food. The process involves the crossbreeding of crops in a laboratory with species that are not plant like. Say for example, that a scientist crossed a fish and a potato. The diversity of this gene mixture is supposed to give this hybrid crop special characteristics like resistance to disease, the ability to deal with extreme environmental situations, and much higher crop yields at harvest time. The production of genetically enhanced food is considered a radical approach to dealing with the world hunger crisis. Critics of gene refined food believe that tampering with the natural order of environmental evolution can be potentially dangerous. "There is an uncertainty about the effects that chemical experimenting could have on non-target species (http://www.globalissues.org/EnvIssues/GEFood/IsGEFoodSafe.asp)." Meaning that scientists fear that extracting genes that perform an apparently useful function as part of a plant or animal may not have the same effects if inserted into a totally unrelated species. These potentially dangerous mixes could create deformed, mutant like crops and animals. The effects that such altered species could have on the environment and peoples overall health is uncertain. Though the process has been proven successful in the lab, many experts feel that serious precautionary measures should be taken before genetically engineered food is mass-produced and sold on the open market. Politics act as the major obstacle in the way of genetically engineered food production. The fact is that legal advances such as copy writes and distribution need to be taken care of first. Despite the advances in genetic food, some forms of these foods still need the aid of pesticides, which are harmful to the soil and insect life. The old saying, "Time is money" can be used to explain why it may be unlikely that these foods will ever make the mainstream market. The red tape surrounding the issue makes the idea of production unattractive to companies who may be interested in investing. Trying to back the production of genetically engineered food would be a bad business move because it is too difficult to get past government health regulations. It would take too long maybe years before bankers would receive returns on their investments. Most analysts of gene enhanced food believe that it is unnecessary to take such an extreme step

Alchemy -The Predecessor of Modern Chemistry

2000-04-11T14:00:00-04:00

There are many ways to examine the subject of alchemy, including alchemy as a source of symbolism, psychology, and mysticism. It has also been an influence on the world view of various writers, artist, and musicians. The focus of this report is alchemy as a pre-chemistry, which gave a new impulse towards the preparation of medicinal remedies and also was a major influence on today's scientific investigations. Alchemy is an ancient art, practiced in the Middle Ages. The fundamental concept of alchemy stemmed from Aristotle's doctrine that all things tend to reach perfection. Because other metals were thought to be less perfect than gold, it was reasonable to believe that nature created gold out of other metals found deep within the earth and that a skilled artisan could duplicate this process. It was said that once someone was able to change, or transmute a "base" chemical into the perfect metal, gold, they would have achieved eternal life and salvation. In this way, alchemy turned into not only a scientific quest, but a spiritual quest as well. Although the purposes and techniques were often times ritualistic and fanciful, alchemy was in many ways the predecessor of modern science, especially the science of chemistry. The birthplace of alchemy was ancient Egypt, where, in Alexandria, it began to flourish during the Hellenistic period. Also at that time, a school of alchemy was developing in China. The writings of some Greek philosophers may be considered to be among the very first chemical theories, such as the theory that all things are composed of air, earth, fire, and water. Each of these were represented by different elements, such as sulfur, salt, mercury, and, ideally, gold. Other ideas held by alchemists were that each of the known elements were represented by heavenly bodies. Gold was earth's representation of the sun, silver for the moon, mercury for the planet Mercury, copper for Venus, iron for Mars, tin for Jupiter, and lead for Saturn. The typical alchemist's laboratory in Renaissance Europe was a dark, cluttered place that stank of smoke and mysterious chemicals. Many alchemists worked at home, in order to save money and avoid outside interference. Some settled in the kitchen, to take advantage of the cooking fire. Others chose the attic or cellar, where late-night activity was less likely to be noticed by inquisitive neighbors. These small, makeshift laboratories were often filled with a grimy jumble of instruments,

Salinity Changes on the polychaete, Nereis succinea

1999-01-22T13:00:00-05:00

I chose to experiment with the effects of salinity changes on the polychaete, Nereis succinea. Along with the other members of the group, Patty and Jeremy, I was curious to see whether the worms would engage in adaptive behavior when placed in a tank of water of foreign salinity, or whether they would simply continue changing osmotically until they reached equilibrium with the environment. The first step in our experiment was to simply observe the worms and get a "feel" for the ways in which they act. We did this on Wednesday, May 7, 1997 from 9:30am to 10:30am. Also on this day we learned how to mix and measure salinity, practiced weighing the worms, and deciding our exact schedule as far as when we would come in and for how long, etc. From what I observed, the polychaete is a salt-water worm that has adapted to live in estuaries. We kept the control tank at 20 parts per thousand to 24 parts per thousand, and the worms seemed very content and healthy at that level. The worms on which we experimented ranged in size from approximately four inches to approximately six inches. They weighed from 1.8 grams to 4.6 grams at the beginning of the experiment. They have a pinkish, almost salmon color to them, and on two opposite sides, they have these crimson hairs lined up in a row, stretching the entire length of their bodies (the hairs are less than an eighth of an inch long). If we were to call the two lines of hair "east and west", then on the "north and south" sides, there were dark lines that also stretched the entire length of their bodies. These were their primary blood vessels, and though we tried to locate the pulse that is supposed to conspicuously travel up and down this vessel, we were not able to l! ocate it, except once on one worm for less than 30 seconds. Also I often was not able to tell the difference between the head and the tail. Their actions were very basic. They seemed to like to stay still for the most part, hiding underneath the little bit of seaweed we put in the tank. We also put a glass tube at the bottom of the tank, thinking that they might try to crawl in there for safety, but we never saw them in there. Basically, they remained very still,

Chemical reactions

1999-01-22T13:00:00-05:00

Chemical reactions are the heart of chemistry. People have always known that they exist. The Ancient Greeks were the firsts to speculate on the composition of matter. They thought that it was possible that individual particles made up matter. Later, in the Seventeenth Century, a German chemist named Georg Ernst Stahl was the first to postulate on chemical reaction, specifically, combustion. He said that a substance called phlogiston escaped into the air from all substances during combustion. He explained that a burning candle would go out if a candle snuffer was put over it because the air inside the snuffer became saturated with phlogiston. According to his ideas, wood is made up of phlogiston and ash, because only ash is left after combustion. His ideas soon came upon some contradiction. When metal is burned, its ash has a greater mass than the original substance. Stahl tried to cover himself by saying that phlogiston will take away from a substance's mass or that it had a negative mass, which contradicted his original theories. In the Eighteenth Century Antoine-Laurent Lavoisier, in France, discovered an important detail in the understanding of the chemical reaction combustion, oxigine (oxygen). He said that combustion was a chemical reaction involving oxygen and another combustible substance, such as wood. John Dalton, in the early Nineteenth Century, discovered the atom. It gave way to the idea that a chemical reaction was actually the rearrangement of groups of atoms called molecules. Dalton also said that the appearance and disappearance of properties meant that the atomic composition dictated the appearance of different properties. He also came up with idea that a molecule of one substance is exactly the same as any other molecule of the same substance. People like Joseph-Lois Gay-Lussac added to Dalton's concepts with the postulate that the volumes of gasses that react with each other are related (14 grams of nitrogen reacted with exactly three grams of hydrogen, eight grams of oxygen reacted to exactly one gram of hydrogen, etc.) Amedeo Avogadro also added to the understanding of chemical reactions. He said that all gasses at the same pressure, volume and temperature contain the same number of particles. This idea took a long time to be accepted. His ideas lead to the subscripts used in the formulas for gasses. From the work of these and many other chemists, we now have a mostly complete knowledge of chemical reactions. There are now

Plutonium: 'Our Country's Only Feasible Solution'

1999-01-22T13:00:00-05:00

Abstract: Should we begin to manufacture one of the most destructive and infamous substances on the face on the Earth once again? The engineers say yes, but the public says no. The United States stopped making this element with the ban on manufacturing nuclear weapons. But with the continuing problem with our ever diminishing energy sources, some want us to begin using more nuclear energy and less energy from natural resources. This paper is going to discuss what plutonium is, the advantages and disadvantages of its use, and why we should think about restarting our production of this useful element. After the United States dropped "Fat Man" and "Little Boy" on Japan ending World War II, the public has had some type of understanding about the power of plutonium and its devastating properties, but that is all anyone heard. After WWII, Americans started to think about what the atomic bomb could do to the U.S. and its people. When anyone mentioned plutonium or the word "nuclear" the idea of Hiroshima or Nagasaki being destroyed was the first thing people thought about. No one could even ponder the idea that it could be used for other more constructive things like sources of energy or to kept a person's heart beating. Then we started to build more reactors and produce more of the substance but mostly for our nuclear weapons programs. Along with reactors, sometimes comes a meltdown which can produce harmful effects if it isn't controlled quickly enough. After such instances as the Hanford, Washington reactor meltdown and the accident in the U.S.S.R. at the Chernobyl site, no one wanted to hear about the use of plutonium. The United States government banned nuclear testing and also ended the production of plutonium.(Ref. 5) Now we are in a dilemma. We are in need of future sources of energy to power our nation. We are running out of coal and oil to run our power plants.(Ref. 7) We also need it to further our space exploration program. People need to understand the advantages to using plutonium and that the disadvantages are not as catastrophic as they seem. With the turn of the century on its way, the reemergence of plutonium production will need to be a reality for us to continue our way of life. In 1941, a scientist at the University of California, Berkeley, discovered something that would change our planet forever. The man's

Niels Bohr's model of the hydrogen atom

1999-01-22T13:00:00-05:00

Niels Bohr's model of the hydrogen atom, was the primary reason for the understanding of energy levels.Bohr was able to explain the bright line spectrum of hydrogen. Sparked by the recent discovery of the diffraction patterns, scientists believed

Representative Gases & Properties of Gases

1999-01-22T13:00:00-05:00

1. State the five assumptions of the Kinetic-Molecular Theory of gases. a) Gases consist of large numbers of tiny particles. These particles, usually molecules or atoms, typically occupy a volume about 1000 times larger than occupied by the same number of particles in the liquid or solid state. Thus molecules of gases are much further apart than those of liquids or solids. Most of the volume occupied by a gas is empty space. This accounts for the lower density of gases compared to liquids and solids, and the fact that gases are easily compressible. b) The particles of a gas are in constant motion, moving rapidly in straight lines in all directions, and thus passes kinetic energy. The kinetic energy of particles overcomes the attractive forces between them except near the temperature at which the gas condenses and becomes a liquid. Gas particles travel in random directions at high speeds. c) The collisions between particles of a gas and between particles and container walls are elastic collisions. An elastic collision is one in which there is no net loss of kinetic energy. Kinetic energy is transferred between two particles during collisions, but the total kinetic energy of the two particles remains the same, at constant temperature and volume. d) There are no forces of attraction or repulsion between the particles of a gas. You can think of ideal gas molecules as behaving like small billiard balls. They move very fast, and when they collide they do not stick together, but immediately bounce apart. e) The average kinetic energy of the particles of a gas is directly proportional to the Kelvin temperature of the gas. The kinetic energy of a particle (or any other moving object) is given by the equation: KE = 1/2mv2. Where m is the mass of the particle and v is the velocity. 2. List the five properties of gases (add the extra one too!) a) Expansion Gases do not have a definite shape of definite volume. They fill the entire volume of an container in which they are enclosed and assume its shape. A gas transferred from 1-L to a 2-L vessel will quickly expand to fill the entire 2-L volume. b) Fluidity Because the attractive forces between gas particles are negligible, gas particles glide easily past one another. This ability to flow causes gases to show mechanical behavior similar to that of liquids. Because liquids and gases flow, they are referred to collectively as