Chemistry 101 - Introduction and Index of Topics

Chemistry 101 - Introduction and Index of Topics Welcome to the world of Chemistry 101! Chemistry is the study of matter. Like physicists, chemists study the fundamental properties of matter and they also explore the interactions between matter and energy. Chemistry is a science, but it is also used in human communication and interaction, cooking, medicine, engineering, and a host of other disciplines. Although people use chemistry every day with no apparent problem, if the time comes to take a course in chemistry in high school or college, many students are filled with dread. Dont be! Chemistry is manageable and even fun. Ive compiled some study tips and resources to make your encounter with chemistry easier. Not sure where to start? Try Chemistry Basics. Periodic Table of the Elements You need a trusty periodic table for practically all aspects of chemistry! There are links to characteristics of elements groups, too. Periodic TablePrintable Periodic TablesGroups of Elements Periodic Table Helpful Resources Use these resources to look up unfamiliar terms, identify chemical structures, and recognize the elements. Worked Chemistry ProblemsChemistry GlossaryChemical Structures ArchiveInorganic ChemicalsElement PhotographsFamous ChemistsScience Lab Safety Signs Introduction to Chemistry 101 Learn about what chemistry is and how the science of chemistry is studied. What Is Chemistry?What Is a Chemical?What Is the Scientific Method? Math Basics Math is used in all the sciences, including chemistry. To learn chemistry, you need to understand algebra, geometry, and some trig, as well as be able to work in scientific notation and perform unit conversions. Accuracy Precision ReviewSignificant FiguresScientific NotationPhysical ConstantsMetric Base UnitsTable of Derived Metric UnitsMetric Unit PrefixesUnit CancellingTemperature ConversionsExperimental Error Calculations Atoms and Molecules Atoms are the basic building blocks of matter. Atoms join together to form compounds and molecules. Learn about the parts of the atom and how atoms form bonds with other atoms. Basic Model of the AtomBohr ModelAtomic Mass Atomic Mass NumberTypes of Chemical BondsIonic vs Covalent BondsRules for Assigning Oxidation NumbersLewis Structures and Electron Dot ModelsIntroduction to Molecular GeometryWhat Is a Mole?More About Molecules MolesLaw of Multiple Proportions Stoichiometry Stoichiometry describes the proportions between atoms in molecules and reactants/products in chemical reactions. Learn about how matter reacts in predictable ways so that you can balance chemical equations. Types of Chemical ReactionsHow to Balance EquationsHow to Balance Redox ReactionsGram to Mole ConversionsLimiting Reactant Theoretical YieldMole Relations in Balanced EquationsMass Relations in Balanced Equations States of Matter The states of matter are defined by the structure of matter as well as whether it has a fixed shape and volume. Learn about the different states and how matter transforms itself from one state to another. States of MatterPhase Diagrams Chemical Reactions Once you have learned about atoms and molecules, youre ready to examine the type of chemical reactions that can occur. Reactions in WaterTypes of Inorganic Chemical Reactions Periodic Trends The properties of the elements exhibit trends based on the structure of their electrons. The trends or periodicity can be used to make predictions about the nature of the elements. Periodic Properties TrendsElement Groups Solutions Its important to understand how substance dissolve and how mixtures behave. Solutions, Suspensions, Colloids, DispersionsCalculating Concentration Gases Gases exhibit special properties based on having no fixed size or shape. Introduction to Ideal GasesIdeal Gas LawBoyles LawCharles LawDaltons Law of Partial Pressures Acids Bases Acids and bases are concerned with the actions of hydrogen ions or protons in aqueous solutions. Acid Base DefinitionsCommon Acids BasesStrength of Acids BasesCalculating pHpH ScaleNegative pHBuffersSalt FormationHenderson-Hasselbalch EquationTitration BasicsTitration Curves Thermochemistry Physical Chemistry Learn about the relationships between matter and energy. Laws of ThermochemistryStandard State ConditionsCalorimetry, Heat Flow and EnthalphyBond Energy Enthalpy ChangeEndothermic Exothermic ReactionsWhat Is Absolute Zero? Kinetics Matter is always in motion! Learn about the motion of atoms and molecules, or kinetics. Factors that Affect Reaction RateChemical Reaction Order Atomic Electronic Structure Much of the chemistry that you learn is associated with electronic structure, since electrons can move around much more easily than protons or neutrons. Valences of the ElementsAufbau Principle Electronic StructureElectron Configuration of the ElementsAufbau Principle Electronic StructureNernst EquationQuantum Numbers Electron OrbitalsHow Magnets Work Nuclear Chemistry Nuclear chemistry is concerned with the behavior of protons and neutrons in the atomic nucleus. Radiation RadioactivityIsotopes Nuclear SymbolsRate of Radioactive DecayAtomic Mass Atomic AbundanceCarbon-14 Dating Chemistry Practice Problems No matter how well you understand the text or the lecture, sometimes you need to see examples of how to approach and solve chemistry problems. Index of Worked Chemistry ProblemsPrintable Chemistry Worksheets Chemistry Quizzes Test your understanding of key chemistry concepts. How to Take a TestAtomic Structure QuizAcids Bases QuizChemical Bonds QuizElement Number QuizElement Picture QuizUnits of Measurement Quiz Science Fair Projects Doing a science fair project? Learn how to use the scientific method to design an experiment and test a hypothesis. Science Fair Project Help Other Useful Stuff Acids and BasesBefore You Buy a Chemistry TextbookCareers in ChemistryHigh School Courses Needed for College ChemLaboratory Safety RulesLesson PlansMaterial Safety Data SheetsStudy TipsTop Chemistry DemonstrationsTop Ways to Fail a Chemistry ClassWhat is the IUPAC?Why Get a Doctoral Degree?Why Students Fail Chemistry

Using the JSON Gem in Ruby

Using the JSON Gem in Ruby Its easy to jump into parsing and generating JSON in Ruby with the json gem. It provides an API for parsing JSON from text as well as generating JSON text from arbitrary Ruby objects. Its easily the most used JSON library in Ruby. Installing the JSON Gem On Ruby 1.8.7, youll need to install a gem. However, in Ruby 1.9.2, the json gem is bundled with the core Ruby distribution. So, if youre using 1.9.2, youre probably all set. If youre on 1.8.7, youll need to install a gem. Before you install the JSON gem, first realize that this gem is distributed in two variants. Simply installing this gem with gem install json will install the C extension variant. This requires a C compiler to install, and may not be available or appropriate on all systems. Though if you can install this version, you should. If you cant install the C extension version, you should gem install json_pure instead. This is the same gem implemented in pure Ruby. It should run everywhere that Ruby code runs, on all platforms and on a variety of interpreters. However, its considerably slower than the C extension version. Once installed, there are a few ways to require this gem. A require json (after a prerequisite require rubygems if needed) will require whichever variant is available and will prefer the C extension variant if both are installed. A require json/pure will explicitly require the pure variant, and a require json/ext will explicitly require the C extension variant. Parsing JSON Before we start, lets define some simple JSON to parse. JSON is typically generated by web applications and can be quite daunting, with deep hierarchies that are difficult to navigate. Well start with something simple. The top level of this document is a hash, the first two keys hold strings and the last two keys hold arrays of strings. { CEO: William Hummel, CFO: Carlos Work, Human Resources: [ Inez Rockwell, Kay Mcginn, Larry Conn, Bessie Wolfe ], Research and Development: [ Norman Reece, Betty Prosser, Jeffrey Barclay ]} So parsing this is quite simple. Assuming this JSON is stored in a file called employees.json, you can parse this into a Ruby object like so. require rubygemsrequire jsonrequire ppjson File.read(employees.json)empls JSON.parse(json)pp empls And this programs output. Note that if youre running this program on Ruby 1.8.7, the order the keys are retrieved from the hash is not necessarily the same order theyre inserted. So your output may appear out of order. {CEOWilliam Hummel, CFOCarlos Work, Human Resources [Inez Rockwell, Kay Mcginn, Larry Conn, Bessie Wolfe], Research and Development [Norman Reece, Betty Prosser, Jeffrey Barclay]} The empls object itself is just a hash. Nothing special about it. It has 4 keys, just as the JSON document had. Two of the keys are strings, and two are arrays of strings. No surprises, the JSON was faithfully transcribed in Ruby objects for your perusal. And thats about all you need to know about parsing JSON. There are some issues that come up, but those will be covered in a later article. For just about every case, you simply read a JSON document from a file or over HTTP and feed it to JSON.parse.

1920s Prohibition and the Rise in Crime essays

1920s Prohibition and the Rise in Crime essays In 1933 the Prohibition on Alcohol was repealed, and the consumption of alcohol was finally made legal, soon after this legalization, Congress passed a law making laws against drugs in the United States. It has been determined by many scholars that ending alcohol prohibition was more harmful in the United States than as it was beneficial. Shortly after this time, a major drug problem began to arise, and the United States has been faced with a drug was ever since. If not for the legalizing of alcohol it is quite possible that our drug epidemic in the U.S. may have been avoided. In 1920, Congress passed the Eighteenth Amendment making alcohol consumption illegal. "The Eighteenth or Prohibition Amendment passed both houses of Congress in December 1917 and was ratified by three-fourths of the 48 state legislatures 13 months later. From 1920 until 1933, the manufacture, sale, and consumption of alcohol was prohibited in the United States./ As with tobacco, the opiates, and cocaine, the legislation failed to create a general climate of abstention. And where there was a populace of willing consumers, supply was still able to keep pace with demand." It was very obvious that during the thirteen years that this act was in effect that there was still a major amount of alcohol being supplied in the country. Many organized crime bosses were in power and dispensing of alcohol and producing all over the country, not to mention local people making it themselves. "Alcohol remained available during Prohibition. People still got drunk, still became alcoholics, still s uffered delirium tremens. Drunken drivers remained a frequent menace on the highways... The courts, jails, hospitals, and mental hospitals were still filled with drunks..." The amendment only had one positive repercussion during its time and that was it did cause fewer people in the United States to consume alcohol. It was very obvious to Congress that the law was ineffective, an...

Reflectivity & appearance Research Paper Example | Topics and Well Written Essays - 750 words

Reflectivity & appearance - Research Paper Example It comes in two forms. One is the cosmetics approach with is also known as aesthetics. This is the surgery that is based on improving certain body parts and features or changing some parts of the body. This is because we want those parts to look the way we want them to look, (CNN, 1999). It’s for beauty and general outlook. The second kind of plastic surgery is the reconstructive surgery which is done to restore some part of the body that has been damaged, (Soueid, 2012). This might have been occasioned by some occurrences like burns, bone fractures and other complicated problems. The reason why a person would want a damaged part of the body to be repaired is to enhance their looks and productivity, (Hettiaratchy & Griffiths, 2011). Personal appearance and productivity are not strange bedfellows. This is because good looks enhance a confident personality, (CNN, 1999). There are occasions that a deformation becomes extreme enough to destroy the personal confidence or even the s elf image. The main reason for a reconstructive surgery is to repair or even correct the problem of a certain malfunctioning part of the body, (Hettiaratchy & Griffiths, 2011). The aim here is to make the part work normally. This happens so that the normal working conditions of a person can be restored, (Siemionow & Klein, 2010). The personality of a person can be affected when some part of the body are not working normally. This is especially so if part of the body is publicly situated, (Stone, 2006). If the correction of the body leads to an improved self esteem, then it can be argued that it improves the personality and confidence. Personality confidence and improved appearance go hand in hand, (Soueid, 2012). Plastic surgeries are not related or even connected to the use of polymers or plastics or synthetics. When a patient undergoes the plastic surgery procedures, they are likely to have some psychological benefits, (Hettiaratchy & Griffiths, 2011). It must be noted that the is sue of personality is completely mental. It therefore, becomes important to correct it using the perception of within the patients mind, (CNN, 1999). Plastic surgery procedure improves the self confidence and esteem, (Siemionow & Klein, 2010). This is because the new looks give those people confidence which is translated into how they relate with other people. Personal confidence is rarely about how other people view it. This is possibly why some people are strongly against it while others are form it, (Rinzler, 2009). The nature of plastic surgery is that it’s supposed to inspire confidence. It addresses the needs of people with a certain need for which they cannot take medicine or fix it in any other way. The people who go for this procedure obtain the desires they aim at. This leads to more comfort while dealing with others. This then, becomes a social factor that is positive, (Papel, 2009). Correcting mark from the face can cause a person to perform better. This also make s those who go for the plastic surgery procedure happier and more comfortable. Personality and individual productivity go hand in hand, (Hettiaratchy & Griffiths, 2011). Few people plan to undergo a plastic surgery; however it becomes hard to put up with a mulled image in case a misfortune happens, (Gunn, 2010). This is because we have a strong attachment to looks and appearance. Plastic surgery has some side effects. People opt to put up with the side effects rather than a damaged skin or body part. This who

Negative Letter Essay Example | Topics and Well Written Essays - 250 words

Negative Letter - Essay Example Since the new policy entered operation, our company has introduced new changes regarding tour and travel services offered to our esteemed clients. Our target currently is families who would wish to enjoy our services. Besides this, we have as well introduced new fun-filled and carefree cruises services that are destined for the beautiful sunny. Not mentioning the exotic ports of call that removes stresses of everyday life from our guests will make my list incomplete. Notably, these changes have attracted more passengers than any other cruise in the world -nearly 4.4million passengers across the whole world. The interviews by our Cruise Week reveal that about 98 percent of our customers are contented with our services. The attached is the schedule for our cruise line starting the week of January 2015. We call for your understanding and promise to dedicate ourselves towards providing you the best quality of our services. I will inform you during the week of January 15 to help you plan special family tour packages that we do

Accounting Controversies Essay Example | Topics and Well Written Essays - 1250 words

Accounting Controversies - Essay Example Deception was the name of the game for Enron. They concealed their controversial and suspicious dealings and transaction with their growing debt so that they appear debt-free and admirable to stockholders and the public. At last, every lie and cover up was made known to many when the company suddenly and unexpectedly filed for Chapter 11 Bankruptcy. That was their last resort. Not even company partnerships and affiliations could save the money and the glory of Enron. When the news of bankruptcy of Enron was revealed, the reasons behind Enron’s downfall remained unclear and uncertain. There were mixed reactions among businessmen, politicians, stockholders and others. Most of them were enraged while some felt concerned. There were those who were not surprise that the discrepancies with the financial statements could actually happen. It was as if it was the common habit among those who wish to decrease their debt. Questions such as the reason behind the downfall as well as the possible ways and means for preventing bankruptcy rose among the interested public. What hindered the company or the government from foreseeing the end of Enron? Was there money laundering or fraud behind the scandal? If there was, has the laws implemented by the government sufficient to verify the financial records of Enron? To shed light on the Enron controversy, a whistleblower, Sherron Watkins, decided to confess all the financial secrets of the company. The government took its role by initiating an investigation powered up by some of the congressional committees. Aside from Watkins, other key players admitted their involvement and decided to testify while some still pleads not guilty. The involvement of an accounting firm as reputable as Arthur Andersen with the controversy, heightened the interest of the public as well as legislators, economists and politicians. The firm also experienced a great loss even though the verdict has not yet been announced. Their clients retracted their loyalty and shifted to other competitive firms. Some employees resigned and sought other jobs from other companies. The accounting firm did a great job on the falsification and manipulation of Enron's financial statements that the discrepancies remained unnoticed to the public and to the government. The implications of the scandal in the political arena was expected since it had close ties with the White House due to the fact that the once prestigious company spent millions of dollars to support Bush's presidential campaign last 2002 elections. Aside from that, Enron's chief executive had personal and friendly relationships with Bush. The latter distanced from Kenneth Lay to prevent any public misconceptions. The investigations of the scandal also revealed that the company requested the presence of two US cabinet members preceding their file for bankruptcy. Even the current vice-president Dick Cheney did not escape the political associations between the government and Enron. The vice resident had several meetings with the executives of the company in lieu of their energy administration plans. The economic implications of the Enron case included the accounting industry's review of their financial policies with the fear of having the same fate as Enron. Other companies who also used the same aggressive accounting methods as Enron have been affected. They steered away from the limelight and have seemed to have lay-low for the meantime while the issues are still steaming. Enron was not the only one negatively affected by the scandal for the same fate went to Arthur Andersen. He was found guilty of destruction of financial records which

Evaluating the success of the tutoring program Case Study

Evaluating the success of the tutoring program - Case Study Example Unlike other programs that are assessed only on the basis of their outcomes, the success of this program will be assessed right from the way it aims to identify the need to its design and finally to the way its objectives and goals defined. According to Richards and Lassonde (2009) a successful tutoring program can be evaluated right from goal setting to curriculum development. The need The success of tutoring program is one that begins by identifying the need for which the program is being designed. For instance, the targeted person may already have some assessment information like retention rates, test scores, and even anecdotal reports from teachers and family. In such a case, the assessment is likely to entail a clear inventory of up-to-date reading aspects, with a clear indication or identification of their scope and nature, in order to effectively measure the need against existing services, as well as to identify the gaps that the new program is intended to fill. This process h elps at minimizing duplication, mobilize resources, build on experience, and avert the tensions that are likely to arise when the new program is rolled out. Most importantly, this information is aimed at helping the planners to concentrate on the kids whose needs are very high. Research shows that, on average, four out of ten kids are at a high risk particularly in terms of developing their level of literacy (Fashola, 2002). The tutoring program in this case was a success as it captured all the aspects mentioned. For instance, picking a child and administering an informal reading inventory. Analyzing and synthesize the results to know the need of the child. Interviewing the student by asking information about her and her family background such as age and language they speak at home. This initial stage was a big success as it helped the teacher to know the need and also to effectively measure the need against available services. Defines the mission A successful tutoring program must have a well-defined overall mission. According to Morrow and Woo (2001) when developing the mission of the program, planners are supposed to take into consideration significant contributions to supporting the child’s literacy development made by institutions such as child care centers, as well as other out-of-school community programs. Therefore, the mission statement must describe what the tutoring program intends to do in order to effectively address the needs identified. In this case, the tutoring program will be successful if its mission is based around the identified needs. In this case, the assessment will want to establish if the need is well identified: the student is female and bilingual. She does not do much reading at home, she like basketball, like Latin music just to mention but a few. In spite of all these, she wants to learn. When some words list and reading stories, started from 3rd grade word lists to 12th grade to read were administered to test her reading s kills, She did well until 6th grade word lists. The instructor was able to notice that she needed instructions and have comprehension problems. Generally, the need for the tutoring program was about reading. Therefore, the mission would read like: The mission of this Tutoring Program is to encourage the student to develop an attitude for reading, to learn, to help the student become an engaged reader, as well as to ensuring that the student has access to high quality reading materials. If the instructor developed a mission statement like this, he could easily proceed as it sets objectives and goals that the tutoring program is expected to deliver. Therefore, a successful tutoring program is assessed on whether or not it has a well-defined mission statement.