Sample Written Report Essay Example for Free

Sample Written Report Essay Introduction: The periodic table is a table in which all of the known elements are listed. The table arranges the elements in order of increasing proton number to show the similarities of chemical elements. Therefore elements with structural similarities atomic number are placed together. These elements can be placed into two different categories, metals non-metals. The early years of the 19th century witnessed a rapid development in chemistry. The art of distinguishing similarities and differences among atoms prompted scientists to devise a way of arranging the elements. Relationships were discerned more readily among the compounds than among the elements; thus, the classification of elements lagged many years behind the classification of compounds. Development of the Periodic Table It was in 1817 when Johann Wolfgang Dà ¶bereiner showed that the atomic weight of strontium lies midway between those of calcium and barium. Some years later he showed that other such â€Å"triads† exist (chlorine, bromine, and iodine and lithium, sodium, and potassium). Another way of classifying the elements was later proposed by John Alexander Reina Newlands in 1864. He proposed that elements be classified in the order of increasing atomic weights. As a result of an extensive correlation of the properties and the atomic weights of the elements in 1869, Dmitri Inovich Mendeleev proposed the periodic law, which states that â€Å"the elements arranged according to the magnitude of atomic masses show a periodic change of properties.† Mendeleev’s Version of Periodic Table The rows 1 to 7 are called periods. The columns I A on the left to 0 on the right are known as groups. Elements with similar properties fall into vertical columns (groups) and horizontal rows (periods), which form the table. The columns in the table are called Groups. The elements in a group have the same number of electrons in their outer shell. Arrangement of the Elements According To Groups Group I A The Alkali Metals Group 1 elements are soft silvery metals. They react strongly with water. The further down the group you go, the more violent this reaction is. These alkali metals are usually stored under oil to protect them from moisture and oxygen. They all have one electron in their outer shells. Group II A – The Alkaline Earth Metals This group consists of all metals that occur naturally in compound form. They are obtained from mineral ores and form alkaline solutions. These are less reactive than alkali metals. Group III A – The Aluminum Group The elements in this group are fairly reactive. The group is composed of four metals and one metalloid which is boron. Group IV A – The Carbon Group This group is composed of elements having varied properties because their metallic property increases from top to bottom meaning the top line, which is carbon, is a nonmetal while silicon and germanium are metalloids, and tin and lead are metals. Group V A – The Nitrogen Group Like the elements in group IV A, this group also consists of metals, nonmetal and metalloids. Group VI A – The Oxygen Group This group is called the oxygen group since oxygen is the top line element. It is composed of three nonmetals, namely, oxygen, sulfur and selenium, one metalloid, (tellurium) and one metal (polonium) Group VII A – The Halogens This group is composed of entirely nonmetals. The term â€Å"halogens† comes from the Greek word hals which means salt and genes which means forming. Halogens group are called â€Å"salt formers†. Group VIII A – The Noble Gases This group is composed of stable gases otherwise known as the non-reactive or inert elements. The Transition Elements The elements in the middle of the table are called transition elements. They are all metals and so they are also called transition metals. Summary A. Development of the Periodic Table 1. Johann Wolfgang Dà ¶bereiner classified elements in sets of three. 2. Dmitri Inovich Mendeleev devised the first periodic table, which he used to predict three new elements. He proposed the†periodic law† which states that when elements are arranged in order of increasing atomic number, their properties show periodic pattern. B. The Periodic Table and the Elements 1. The periodic table is composed of 7 rows or periods and 18 major groups or columns. 2. The elements are given symbols devised by John Jacob Berzelius. An element is named after its discoverer, place of discovery, first letter of the name of the element, first and the second letter for those having the same first letter and some are after their Latin names. The elements are grouped into Group A and B Group by the INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY (IUPAC). 3. Elements in the periodic table are also grouped according to metals, non-metals and metalloids. Metals are lustrous, malleable and ductile. They are good conductors of heat. Metals are found on the left side of the periodic table. Nonmetals have a diverse set of properties. They are found on the upper right side of the periodic table. Metalloids or semimetals possess the properties of both the metals and the non-metals. Conclusion The Periodic Table of Elements supports Chemistry, as it explains periodic law and the significance of the rows and columns of the periodic table, including how to relate the position of an element in the table to its atomic number and atomic mass. Students comprehension of the significance of the table will be reinforced as they learn how to use it to identify metals, semimetals, nonmetals and halogens, as well as the relative sizes of ions and atoms. The program also outlines the physical and chemical qualities of the members of each group of elements from the alkaline metals to the noble gases.

Shakespeares Hamlet - The Importance of the Ghost Essay -- GCSE Engli

Hamlet and the Non-expendable Ghost   Ã‚   All literary critics agree that the Ghost in Shakespeare’s tragedy Hamlet is not an expendable character. Without the Ghost the show could not go on. He is absolutely essential to the plot, to ever aspect of the drama.    W.H. Clemen in â€Å"Imagery in Hamlet Reveals Character and Theme† describes the pervasive influence which the Ghost’s words have on the entire play:    Perusing the description which the ghost of Hamlet’s father gives of his poisoning by Claudius (I,v) one cannot help being struck by the vividness with which the process of poisoning, the malicious spreading of the disease, is portrayed:    Sleeping within my orchard,   Ã‚  Ã‚  Ã‚   My custom always of the afternoon,      Ã‚  Ã‚  Upon my secure hour thy uncle stole,   Ã‚  Ã‚  Ã‚   With juice of cursed hebenon in a vial,   Ã‚  Ã‚  Ã‚   And in the porches of my ears did pour   Ã‚  Ã‚  Ã‚   The leperous distilment; whose effect   Ã‚  Ã‚  Ã‚   Holds such an enmity with blood of man   Ã‚  Ã‚  Ã‚   That swift as quicksilver it courses through   Ã‚  Ã‚  Ã‚   The natural gates and alleys of the body,   Ã‚  Ã‚  Ã‚   And with a sudden vigour doth posset   Ã‚  Ã‚  Ã‚   And curd, like eager droppings into milk,   Ã‚  Ã‚  Ã‚   The thin and wholesome blood: so did it mine;   Ã‚  Ã‚  Ã‚   And a most instant tetter bark'd about,   Ã‚  Ã‚  Ã‚   Most lazar-like, with vile and loathsome crust,   Ã‚  Ã‚  Ã‚   All my smooth body.    A real event described at the beginning of the drama has exercised a profound influence upon the whole imagery of the play. What is later metaphor is here still reality. The picture of the leprous skin disease, which is here – in the first act – described by Hamlet’s father, has buried itself deep in Hamlet’s imagination and continues to lead its subterranean existence, as ... ...Hamlet. Ed. Don Nardo. San Diego: Greenhaven Press, 1999. Rpt. from The Masks of Hamlet. Newark, NJ: University of Delaware Press, 1992. Shakespeare, William. The Tragedy of Hamlet, Prince of Denmark. Massachusetts Institute of Technology. 1995. http://www.chemicool.com/Shakespeare/hamlet/full.html Ward & Trent, et al. The Cambridge History of English and American Literature. New York: G.P. Putnam’s Sons, 1907–21; New York: Bartleby.com, 2000 http://www.bartleby.com/215/0816.html West, Rebecca. â€Å"A Court and World Infected by the Disease of Corruption.† Readings on Hamlet. Ed. Don Nardo. San Diego: Greenhaven Press, 1999. Rpt. from The Court and the Castle. New Haven, CT: Yale University Press, 1957. Wilkie, Brian and James Hurt. â€Å"Shakespeare.† Literature of the Western World. Ed. Brian Wilkie and James Hurt. New York: Macmillan Publishing Co., 1992.

Discuss the Use and Impacts of Anabolic Steroids on the Human Body

Human understanding of anabolic steroids began when Arnold Adolph Berthold (1849) demonstrated loss of male characteristics in testes-deprived cockerels. Experiments carried out in castrated dogs and later in humans demonstrated the anabolic effects of testosterone (Kochakian, 1936). Testosterone became the first ever synthetic anabolic steroid when created from cholesterol and from which all the steroids used currently are derived.Anabolic steroids exert their anabolic effects on muscle and bone, and their androgenic effects on hair follicles in the skin, the liver and kidneys, and the haematopoietic, immune and central nervous systems (Mooradian et al. , 1987). Thus their ergogenic properties promote human secondary sexual characteristics, such as muscular growth and physical strength (Evans, 2004). Steroids are relatively small molecules and they can passively diffuse into cells.In target tissues, that is, the cells that contain steroid receptors, the hormone binds to the receptor ligand-binding domain, causing the receptor to change from an inactive to active state. In target tissues where intracellular enzymes are present, the action of testosterone is mediated by metabolism. Testosterone is irreversibly converted by the enzyme 5a-reductase to 5a-dihydrotestosterone (DHT), which binds with greater affinity to the androgen receptor, or by aromatase to oestradiol, which binds to the oestrogen receptor (Shahidi, 2001).Testosterone and DHT can be also converted to weaker androgens, again being dependent on whether the target tissue has the necessary enzyme activity, e. g. , 3a-hydroxysteroid dehydrogenase, 17ß-hydroxysteroid dehydrogenase. With structural modifications to testosterone, the anabolic effects of androgens can be enhanced but, even so, these cannot be divorced entirely from their androgenic effects. Hence, a more accurate term for anabolic steroids is anabolic–androgenic steroids [AAS] (Kuhn, 2002).The widespread use of anabolic steroids started during World War II, when it was found that this artificial form of testosterone could be used to help malnourished soldiers gain weight and improve performance. After the war, athletes began to use steroids to enhance their performance in competitions. In the 1956 Olympics, Soviet athletes, especially wrestlers, performed at exceptionally high levels. After learning that those athletes were using testosterone, Dr. Zeigler, an American physician created a more selective form, of what we know as anabolic steroids.From that point until the early 1970’s, steroids became increasingly popular among not just Olympic athletes, but also professional sports players and high school athletes. In 1975, the International Olympic Committee finally banned the use of steroids in Olympic competition. Although anabolic steroids are controlled substances in several countries, their use for cosmetic purposes such as development of bulging muscles and a well-toned figure is not uncommon since, it is considered a harmless manipulation.Use of these AAS involves several risks that could cause problems in both the short and long term. Prolonged use of anabolic steroids increases one’s risk of sudden death due to serious conditions like ventricular hypertrophy, thrombo-embolism and cerebro-vascular disorders. However, the cardiovascular consequences of supra- physiological androgen levels had not been determined fully until now. A research study revealed that AAS caused the impairment of vascular reactivity.It also revealed that abstention from AAS consumption, significantly improves vascular functions (Lane et al, 2006). Anabolic steroid use may also cause muscle and tendon tears, acne, liver cirrhosis, abnormal increase in cholesterol levels, and bipolar and aggressive behavior. Females undergo a deepening of the voice, increased hair loss, facial hair growth and depletion of female hormones, like estrogen and progesterone.The most common problems for male user s are reduced testosterone production, resulting in the shrinking of their testicles; erectile dysfunction, reduced sperm production and reduced sperm count. In teenagers, the continued use of AAS stops bone development (Kicman, 2008). Conversely, AAS also corrects physical problems and are employed in treatment of cachexia associated with chronic disease states, to increase testosterone levels and their effects in males whose levels are below ‘normal’ (Lew, 2007).Only relatively recently that these agents are being revisited for clinical purposes and their efficacy still needs to be demonstrated in terms of improved physical function and quality of life. For clinical purposes, the administration of these drugs can be of therapeutic benefit and reasonably safe, with the physician making objective decisions based on the benefit/risk ratio in relation to a patient's condition.Hence it is important not to overstate the medical risks associated with anabolic steroid use (Ho ffman and Ratamess, 2006) but to emphasize that the hazards to health are dependent on the sex, the dose, the duration of administration, whether hepatoxic 17a-alkylated steroids are being administered and the susceptibility of the individuals themselves to androgen exposure which is probably dependent on genetic factors, age and lifestyle.

Essay on Raphael Sanzios Life and Accomplishments

Raffaello Sanzio was an amazing artist from the late 1400’s to the early 1500’s, who created many amazing paintings that helped change the style of medieval art to Renaissance art. Without him, the style of art now would most likely be more primitive and not as advanced as it should be. This is because he made many advances including more realistic painting. His most important paintings include â€Å"The School Of Athens†, the â€Å"Sistine Madonna†, and the â€Å"Marriage of the Virgin†. Not only are those some of his most famous paintings, they also show the realisticness that changed the world. Raffaello Sanzio had a very interesting young life. He was born in Urbino, which at the time was a cultural center that encouraged the arts. The arts†¦show more content†¦He was his apprentice at the town of Perugia. Since Perugino was a master painter this greatly influenced Raphael’s young life and encouraged him to become an artist. Raphael, before exiting apprenticeship, made a few amazing paintings. These include the Mond Crucifixion, The Three Graces, The Knight’s Dream, and The Marriage of the Virgin, which I will mention later. Raphael made many very detailed paintings. My choices for his most contributing paintings are The School of Athens, The Sistine Madonna, and The Marriage of The Virgin. They were just a few of the many amazing paintings that Raphael has painted. The School of Athens was possibly Raphael’s most popular painting. It shows representations of many mathematicians, philosophers, and scientists of the Renaissance. The two people walking down the middle of the hall are Aristotle and Plato who were very important contributors to the way of western thinking, and in different ways, their philosophies were incorporated into Christianity. Plato is holding the book called The Timaeus. Plato points up because in his philosophy the changing world that we see around us is just a shadow of a higher, truer reality that is eternal and unchanging (and include things like goodness and beauty). Aristotle holds his hand down, because in his philosophy, the only reality is the reality that we can see and