Mercury Essays (520 words) - Matter, Health, Chemistry, Mercury

Mercury Mercury Atomic Number: 80 Latin: hydrargyrum ?liquid silver? Atomic Symbol: Hg Atomic Weight: 200.59 Mercury is the only common metal that is a free-flowing liquid at room temperature. It is slightly volatile in room temperature and becomes solid when subjected to a pressure of 7640 atmospheres. The metal dissolves in nitric or concentrated sulfuric acid. The chief ore is cinnabar; Spain and Italy produce about 50% of the world's supply of the metal. The commercial unit for handling mercury is the ?flask,? which weighs about 76 pounds. The metal is obtained by heating cinnabar in a current of air and by condensing the vapor. The metal is widely used in laboratory work for making thermometers, barometers, diffusion pumps and many other instruments. It is used in making mercury vapor lamps, advertising signs, mercury switches and other electronic apparatus. Other uses are in making pesticides, dental preparations, antifouling paint, batteries and catalysts. The most important salts are mercury chloride (a violent poison), mercurous chloride (occasionally still used in medicine), mercury fulminate (detonator widely used in explosives) and mercuric sulfide (a high-grade paint pigment). Mercury is a virulent poison and is readily absorbed through the respiratory tract, the gastrointestinal tract, or through unbroken skin. Most human exposure is by inhalation. Air saturated with mercury at 20 degrees C contains a concentration that exceeds the toxic limit many times. Mercury vapor diffuses across the alveolar membrane without difficulty. It is lipid soluble therefore it can get into the blood stream and has a strong affinity for the central nervous system. The danger increases at higher temperatures thus it's important that mercury be handled with care. Chronic mercury poisoning causes irreversible brain, liver and kidney damage. For example, Minamata disease was discovered in 1956 and in 1968 it was announced that it was a pollution disease caused by the Chisso Co. Ltd. The Chisso Company polluted Minamata Bay of Japan with factory wastewater that contained methyl mercury. The methyl mercury got into the fish and people of Japan ate the fish and got the disease. The methyl mercury that entered the body mainly attacked the central nervous system, including the brain and caused various symptoms including numbness and unsteadiness in the legs and hands, tiredness, ringing in the ears, narrowing of the field of vision, loss of hearing, slurred speech, and awkward movements. Some early severe victims of Minamata disease went insane, became unconscious, and died within a month of the onset of the disease. There are also victims with chronic symptoms, such as headaches, frequent tiredness, loss of the senses of smell and taste, and forget fulness, which are not easily visible but make daily life difficult. Moreover, there are congenital Minamata disease patients, who were born with handicaps after being attacked by methyl mercury while in the wombs of their mothers who consumed polluted fish. No fundamental cure for Minamata disease has yet been discovered, so treatment consists of attempts to lessen the symptoms and physical rehabilitation therapy. Bibliography Bibliography Klaassen, Curtis D. Casarett & Doull's Toxicology The Basic Science of Poisons, 1996 McGraw-Hill, p 710 Microsoft Encarta Online Encyclopedia 2000. ?Mercury (element)? http://encarta.msn.com Science

Practice English Using This Dialogue With a Famous Actor

Practice English Using This Dialogue With a Famous Actor Use this interview with a famous actor to practice speaking and pronunciation skills, as well as review important grammar points on tense usage. Read, practice with a partner, and check your understanding of important vocabulary and grammar points. Finally, create a dialog of your own with exercise cues. Interview Part 1: Practice Using the Present Simple and Present Continuous The first part of  the dialog concerns daily routines, as well as current activities.  Notice that the  present simple  is used to speak and ask about daily routines: He usually gets  up early and goes to the gym.How often do you travel for work?She doesnt work from home.   The  present continuous  is used to speak about what is happening at this specific moment in time, as well as around  the current moment in time: Im studying French for a test right now. (at this moment)What are you working on this week? (around current moment)Theyre getting ready to open the new store. (at this moment / around current moment) Interviewer: Thank you for taking some time off from your busy schedule to answer a few questions about your life!Tom: Its my pleasure. Interviewer: Could you tell us about an average day in your life?Tom: Sure, I get up early, at 7 in the morning. Then I have breakfast. After breakfast, I go to the gym. Interviewer: Are you studying anything now?Tom: Yes, Im learning dialog for a new film called The Man About Town. Interviewer: What do you do in the afternoon?Tom: First I have lunch, then I go to the studio and shoot some scenes. Interviewer: Which scene are you working on  today?Tom: Im acting out a scene about an angry lover. Interviewer: Thats very interesting. What do you do in the evening?Tom: In the evening, I go home and have dinner and study my scripts. Interviewer: Do you go out at night?Tom: Not always, I like going out at weekends. Interview Part 2: Practice Using the Present Perfect and Future Tenses The second section of the interview focuses on the actors experience from the past to  the present. Use the  present perfect  when speaking about experience over time: Ive visited many countries throughout the world.Hes made more than fifteen documentaries.Shes worked at that position since 1998. The  future forms  going to  and  will  are used to speak about the future. Notice that  going to  is used with future plans whereas  will  is used to predict the future. Im going to visit my uncle next week.Theyre going to open up a new store in Chicago.I think Ill take a vacation in June, but Im not sure.She thinks hell get married soon. Interviewer: Lets talk about your career. How many films have you made?Tom: Thats a hard question. I think Ive made more than 50 films! Interviewer: Wow. Thats a lot! How many years have you been an actor?Tom: Ive been an actor since I was ten years old. In other words, Ive been an actor for twenty years. Interviewer: Thats impressive. Do you have any future projects?Tom: Yes, I do. Im going to focus on making a few documentaries next year. Interviewer: That sounds great. Do you have any plans beyond that?Tom: Well, Im not sure. Maybe I will become a film director, and maybe Ill just retire. Interviewer: Oh, please dont retire! We love your films!Tom: Thats very kind of you. Im sure Ill make a few more films. Interviewer: Thats good to hear. Thank you for the interview.Tom: Thank you. Practice Exercise: Create Your Own Dialogue Use these cues to create your own dialogue with a famous actor. Pay careful attention to the time words and context to help you choose the correct tense. Try to come up with different possibilities.   Interviewer: Thank you / interview. Know / busyActor: Welcome / Pleasure Interviewer: work new film?Actor: Yes / act in Sun on My Face this month Interviewer: congratulations. Ask questions about life?Actor: Yes / any question Interviewer: what do after work?Actor: usually relax pool Interviewer: what do today?Actor: have interview today! Interviewer: where go evening?Actor: usually stay home Interviewer: stay home this evening?Actor: no go movies Interviewer:   which movie?Actor:  not say Example Solution: Interviewer:  Thank you for letting me interview you today. I know how busy you are.Actor:  Youre welcome. It was  a pleasure to meet you. Interviewer:   Are you working on a new film these days?Actor: Yes, Im acting in Sun in My Face this month. Its a great film! Interviewer:   Congratulations! May I ask you some questions about your life?Actor:  Of course you can! I can answer almost any question! Interviewer:   Great. So, acting is hard work. What do you like doing after work?Actor:  I  usually relax at my pool.   Interviewer:   What are you doing today for relaxation?Actor: Im having an interview today!   Interviewer:   Thats very funny! Where do you enjoy going in the evening?Actor: I usually just stay home! Im boring! Interviewer:   Are you staying home this evening?Actor: No. This evening Im going to the movies. Interviewer:   Which movie are you going to?Actor: I cant say. Its a secret! Key Vocabulary take time off   stop working in order to do something elseaverage day   a normal or typical day in someones lifestudio   the room(s) in which a movie is madeshoot some scenes   act scenes from a movie for the camerascript   the lines the actor needs to speak in a moviecareer   your job or work over a long period of timefuture projects   work that you will do in the futurefocus on something   try to do only one thingdocumentary   a type of film about something that happened in real liferetire   stop working