Tin Hedgehog Experiment - Grow Tin Metal Crystals

Metal crystals are intricate and beautiful. They are also surprisingly easy to grow. In this experiment, learn how to grow tin crystals that display a spiky appearance that make them look like a metal hedgehog. Tin Hedgehog Materials 0.5 M tin(II) chloride solution (SnCl2)zinc pellettest tube or vial that is larger in diameter than the zinc The rounded hedgehog shape forms around a pellet of zinc, but you can substitute any chunk of zinc metal. Since the reaction occurs at the surface of the metal, you may also use a galvanized (zinc coated) object in place of the zinc pellet. Grow a Tin Hedgehog Pour tin chloride solution into a vial. Dont fill it up all the way because you need room for the zinc.Add the zinc pellet. Set the vial somewhere stable, so it wont get bumped or jarred.Watch the delicate tin crystals grow! Youll see the beginning of a spiky hedgehog shape in the first 15 minutes, with good crystal formation within an hour. Be sure to take pictures or video of the crystals for later, since the tin hedgehog wont last. Eventually, the weight of the fragile crystals or movement of the container will collapse the structure. The bright metallic shine of the crystals will dull over time, plus the solution will turn cloudy. Chemistry of the Reaction In this experiment, tin(II) chloride (SnCl2) reacts with zinc metal (Zn) to form tin metal (Sn) and zinc chloride (ZnCl2) via a substitution or single displacement  reaction: SnCl2   Zn → Sn ZnCl2 Zinc acts as a reducing agent, giving electrons to the tin chloride so that the tin is free to precipitate.  The reaction begins at the surface of the zinc metal. As the tin metal is produced, atoms stack on top of each other in a characteristic form or allotrope of the element. The fern-like shape of the zinc crystals is a characteristic of that metal, so while other types of metal crystals may be grown using this technique, they wont display the same appearance. Grow a Tin Hedgehog Using an Iron Nail Another way to grow tin crystals is using zinc chloride solution and iron. Unless you use a round chunk of iron, you wont get a hedgehog, but you can get the crystal growth, just the same. Materials iron wire or nail0.1 M tin chloridetest tube Note: You dont need to make up a new tin chloride solution. If you have solution from the reaction with zinc, you can use that. The concentration mainly affects how quickly the crystals grow. Procedure Suspend the iron wire or nail in a test tube containing tin chloride.After about an hour, crystals will start to form. You can examine these with a magnifying glass or by removing the wire and looking at the crystals under a microscope.Allow the iron to remain in the solution overnight for more/larger crystals. Chemical Reaction Once again, this is a  simple displacement chemical reaction: Sn2   Fe → Sn Fe2 Safety and Disposal As always, its good practice to wear safety goggles and gloves when performing chemistry experiments.When you have finished the experiment, you can rinse the chemicals down the drain with water. Learn More Use a magnifying lens to compare tin crystals grown on the zinc and iron surfaces.You may wish to experiment with how changing the concentration of the zinc chloride solution or temperature of the solution affects the crystal growth rate and appearance.Try to grow other metal crystals using this technique. Keep in mind the resulting crystals might not resemble a hedgehog. To choose a subject, find a metal salt that is soluble in water, does not oxidize too quickly in air, yet can react with zinc or iron (or other metal) to form crystals. The metal needs to be more reactive than tin or the substitution wont proceed.  Its also a good idea to consider the toxicity of the metal, for personal safety and chemical disposal. You can consult the solubility rules to select good candidates for further experimentation. Sources Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1985). Tin. Lehrbuch der Anorganischen Chemie (in German) (91–100 ed.). Walter de Gruyter. pp. 793–800. ISBN 3-11-007511-3.Schwartz, Mel (2002). Tin and Alloys, Properties. Encyclopedia of Materials, Parts and Finishes (2nd ed.). CRC Press. ISBN 1-56676-661-3.

Essay about Analysis of Hemingways Soldiers Home

Essay #1: Characterization Title: â€Å"Soldier’s Home† Author: Ernest Hemingway Setting: Post World War I era, 1919. In Howard’s (Kreb’s) quaint home town in Oklahoma. All who have returned from the harsh war are welcomed; their stories as well. All except for Krebs. Narrative Point of View: 3rd person. The narrator puts the reader in Kreb’s environment or in his society, so to speak. This allows one to feel as Krebs does and better understand the lasting effects of war (or perhaps the lasting effects of his lies) on him and the surrounding characters Conflict(s): Man vs. Himself: Krebs is dealing with the complications of reestablishing himself in society after the complications of a restless war. He becomes angry at himself as†¦show more content†¦Literary Device Focus: Elements of Characterization- Background, Actions, Motivation, Author’s Implied Evaluation Mike Egan Ernest Hemingway’s â€Å"Soldiers Home† is about a young man named Krebs who is learning to adjust to society after his experience in Europe during World War I. Hemingway’s purpose for writing this story can be confusing and also very telling. I believe Krebs was not a soldier at all and in fact, deceives his family, his friends, and his community into believing he was an experienced soldier in World War I. At first glance, Krebs may be seen as a war hero. However, by observing the characteristics such as Kreb’s background, actions, motivation, and the author’s Implied Evaluation, we see that he is not a war hero at all. Hemingway begins by saying Krebs went to a Methodist college fraternity where they wore, â€Å"exactly the same height and style collar,† (272) indicating that they were neatly dressed and proper. This is an indication that Krebs came from an environment that required uniformity. In the next paragraph, Hemingway also describes how Krebs is seen in a picture near the Rhine river soon after his enrollment where, â€Å"Krebs and the corporal look too big for their uniforms,† and, â€Å"The Rhine does not show in the picture,† (272) which leads the reader to believe that there is no solid proof that Krebs was ever in Germany during the war. People begin toShow MoreRelatedAnalysis of Hemingways Soldiers Home1080 Words   |  4 Pages A Soldiers Home The contents in this book have the purpose to open up and provoke a reaction from the readers. The author writes with the intention being to get a reaction from the readers concerning war. War is never easy for anyone. This is independent of whether the person is a participant in the war or from the point of perspective of the observer. The families of the soldiers also have an alteration in their lives. War is never an easy occurrence and has by far serious implications and significanceRead MoreAnalysis of Literary Devices in Soldiers Home Essay951 Words   |  4 Pagesâ€Å"Soldier’s Home by Ernest Hemingway Ernest Hemingway â€Å"Soldier’s Home is an outstanding short story that shows the tragic impact of war on the life of a young soldier who returns home. The story paints a vibrant picture of a soldier’s life after coming back from a shocking experience. Hemingway shows impacts of war on a soldier with the main character being Harold Krebs, who faces hostility in his hometown after his return from fighting in the war. The main character in the story is Kreb withRead More Comparing Loss of Self in Soldiers Home, Pauls Case, and Bartleby1442 Words   |  6 PagesLoss of Self in Hemingways Soldiers Home, Cathers Pauls Case, and Melvilles Bartleby the Scrivener  Ã‚     Ã‚  Ã‚   Hemingways Soldiers Home, Cathers Pauls Case, and Melvilles Bartleby the Scrivener all present a loss of self. These stories prove that there is a fine line between finding ones self and losing ones self. I believe this loss can occur at any age or station of life. This idea is seen in each storys main character. Hemingways Soldiers Home depicts a young man inRead MoreA Soldiers Home Setting Analysis Essay examples707 Words   |  3 PagesOctober 2012 A Soldier’s Home: Setting Analysis In Ernest Hemingway’s short story â€Å"A Soldier’s Home†, Krebs, a soldier, returns to his hometown from fighting in World War I. As indicated throughout the story, â€Å"home† for Krebs is not unlike the war front: confusing, complicated, and restless. Hemingway uses the setting in Kansas, during World War I, to convey Krebs post-war life in comparison to his pre-war. The title â€Å"Soldiers Home† reveals the question; where is the soldier’s home? In the shortRead More Deceitfulness in The Scarlet Letter and The Catcher in the Rye2027 Words   |  9 Pagesschool and roams the streets of New York for a couple of days before returning home where he meets new people. Holden finds out more about himself and how he relates to the world around him. He briefly enters what we believes is adulthood and becomes a â€Å"phony† himself. By the end of the story, Holden realized he doesn’t like the type of person he has become, so he turns back into a negative, judgmental person. The analysis of the main characters, Hester, Dimmesdale, Chillingworth, and Holden of TheRead MoreConflict Management and Emotional Intelligence63003 Words   |  253 Pages96                                                         3.2       Justification  for  the  paradigm  and  methodology                                       99                           99                              96   3.2.1    Qualitative  analysis  Ã‚   chosen                     3.2.2    Unit  of  analysis                 Ã‚  Ã‚  Ã‚  Ã‚   3.2.3    Instruments  and  procedures  of  data  collection                              107   3.2.4    Administration  of  instruments  and  procedures                              113

The Betrayal and Loyalty in Macbeth and Kite Runner

â€Å"A boy who won’t stand up for himself becomes a man who can’t stand up to anything.† Baba says these words to Rahim Khan while he is talking about Amir at the end of Chapter 3, and the quotation reveals important traits in both Amir and Baba. With these words, Baba sums up one of Amir’s major character flaws—his cowardice—and Baba shows how much value he places in standing up for what is right. Baba is reluctant to praise Amir, largely because he feels Amir lacks the courage to even stand up for himself, leaving Amir constantly craving Baba’s approval. Amir’s desire for this approval as well as his cowardice later cause him to let Assef rape Hassan. The quotation also foreshadows the major test of Amir’s character that occurs when he†¦show more content†¦In contrast with this, the most loving relationship between father and son we see is that of Hassan and Sohrab. Hassan, however, is killed, and toward the end of the novel we watch Amir trying to become a substitute father to Sohrab. Their relationship experiences it s own strains as Sohrab, who is recovering from the loss of his parents and the abuse he suffered, has trouble opening up to Amir. When we got to Kabul, I [Rahim Khan] discovered that Hassan had no intention of moving into the house. But all these rooms are empty, Hassan jan. No one is going to live in them, I said. But he would not. He said it was a matter of ihtiram, a matter of respect. He and Farzana moved their things into the hut in the backyard, where he was born. I pleaded for them to move into one of the guest bedrooms upstairs, but Hassan would hear nothing of it. What will Amir agha think? he said to me. What will he think when he comes back to Kabul after the war and finds that I have assumed his place in the house? Then, in mourning for your father, Hassan wore black for the next forty days. (16.24-25) You may be confused by the voice here. Its actually not Amir – Rahim Khan gets one chapter in the book. Rahim Khan recounts his trip to Hazarajat to find Hassan and bring him back to the house in Kabul. When

Entity Relationship Diagram

Question: Discuss about the Entity Relationship Diagram. Answer: Business Rules/Assumptions Some assumptions and business rules have been followed in the database development The address, telephone and mobile numbers of applications, members and site inspectors. All types of applications will be saved in separate tables to fetch the data easily. The reason of objections is mandatory to store into the database. The detail of cleared applications is also mandatory to store in the database. Logical Design / 3NF Relations Applicants (ApplicantID, Name, Address, TelPhoneNumber, Mobile) SuburbanArea (SubAreaID, Address, Length, Width) Lots (LotNumber, SubAreaID, Boundary1, Boundary2, Boundary3, Boundary4) Foreign Key (SubAreaID) References SuburbanArea (SubAreaID) Application (ApplicationID, ApplicationIssueDate, Detail, ApplicantID, LotNumber) Foreign Key (LotNumber) References Lot (LotNumber) Foreign Key (ApplicantID) References Applicants (ApplicantID) TreeRemoval (ApplicationID, NumberofTress, TotalCharges) Extension (ApplicationID, TotalCharges) Demolition (ApplicationID, TotalCharges) Construction (ApplicationID, TotalCharges) LotDivision (ApplicationID, TotalCharges) LotMerging (ApplicationID, TotalCharges) Members (MemberID, Name, Address, TelPhoneNumber, Mobile) Objections (ObjectionID, MemberID, ApplicationID, ObjectionIssueDate, ReasonofObjection) Foreign Key (ApplicationID) References Application (ApplicationID) Foreign Key (MemberID) References Members (MemberID) SiteInspector (ID, Name, Address, TelPhoneNumber, Mobile) ClearedApplications (ClearanceNumber, ApplicationID, ClearanceIssueDate, Detail) Foreign Key (ApplicationID) References Application (ApplicationID) InspectionReports (ClearanceNumber, ID, InspectionVisitDate, Details) Foreign Key (ClearanceNumber) References ClearedApplications (ClearanceNumber) Foreign Key (ID) References Inspector (ID) (TechTarget 2016) (Smartdraw 2016) References TechTarget (2016), entity relationship diagram, Available: https://searchcrm.techtarget.com/definition/entity-relationship-diagram. [Accessed: 15-August-2016] Smartdraw (2016), Entity Relationship Diagram, [Online]. Available: https://www.smartdraw.com/entity-relationship-diagram/. [Accessed: 15-August-2016] Freetutes.com (n.d.), Types of attributes, [Online]. Available: https://www.freetutes.com/systemanalysis/sa7-types-of-attributes.html. [Accessed: 15-August-2016] Edugrabs.com (2015), Types of Attributes in DBMS with Example (ER MODEL Part 2), [Online]. Available: https://www.edugrabs.com/type-of-attributes-in-dbms/. [Accessed: 15-August-2016]