...Fundamental Structures and Properties of Teflon and Its Applications in Industry 1. Introduction Polytetrafluoroethylene (PTFE) also known as Teflon is a thermoplastic polymer. It is formed by addition polymerization using the monomer tetrafluroethylene (TFE). Teflon is a strong, waxy and non-flammable resin which is used in many applications especially in corrosive industries due to its resistance to chemicals. In addition, it is able to maintain its physical properties over a wide range of temperatures. Teflon was invented by accident by a research chemist named Roy J. Plunkett at DuPont’s Jackson Lab in New Jersey on 6 April 1938. Plunkett and his technician assistant, Jack Rebok, were testing on the chemical reactions of the refrigerant gas TFE, he noticed one of the pressurized cylinders failed to discharge when its valve was opened. Rebok suggested cutting the cylinder open to see what went wrong. They discovered the gas inside the cylinder had solidified into a white powder. Plunkett began to test the properties of the white powder. The white powder was found to be more lubricant than other slippery solids. In addition, it proved to be inert to almost other chemicals and had extremely high melting point at 335°C. Plunkett discovered that the gas had polymerized to become a PTFE resin and thus, invented a way to produce the TFE to PTFE polymerization in the lab. 2. Analysis of Fundamental Structures and Properties PTFE exhibits many useful properties. It is resistant...
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...Fluoride Fluoride is mineral, traditionally known for its use in keeping our teeth clean, strong and preventing tooth decay. Although Fluoride helps our teeth, it does not help with the growth of our bodies, so is not practically considered a mineral essential for health and well being. It has been around for a long time and it is used in today’s society a lot. Fluoride was discovered by Henri Moissan in 1886, a French chemist that found fluoride in a hydrogen fluorine gas mix. It wasn’t discovered to help with tooth decay until 1936, when they did a study with fluoridated water in cities in Colorado Springs. Our bodies only need a small amount of fluoride in our bodies and 95% of that can be found in our skeletal system. The way fluoride helps our teeth is, by interacting with calcium and phosphate to help mineralize broken down tooth enamel. It has been found that children that consume a sufficient amount of Fluoride when their teeth are starting to develop and come through, have greater protection from tooth decay for the rest of their lives. Fluoride not only helps protect our teeth by prevent decay; it also helps strengthen our bones. Our body absorbs fluoride through the stomach and small intestine, for where it eventually ends up in our bloodstream. Once there it gets into our bones and teeth, and doesn’t build up in our soft tissue. Fluoride deficiency has been proven in communities where fluoridated water has not been introduced yet. It has been proven that...
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...The Elucidation of Fluoridation Fluoride. What is it? A nutrient? A medication? A pollutant? Water fluoridation has been a popular matter that has been going on for years. Many cities have been implementing fluoride in public water systems and many have not. The reason behind water fluoridation is that can help tooth decay. But fluoride’s adverse effects prevent some cities from imposing this practice. Water fluoridation should not be implemented within public water systems due to its effects on health, its environmental impact, and it being an unethical health intervention. Fluoride has gained its popularity in attempts to prevent tooth decay and dental caries, otherwise known as cavities. It has been incorporated into oral health products, such as toothpaste and mouthwash, acting as a topical treatment, but such dental treatments didn't stop there. Fluoride compounds have been added to public water supplies ever since the early 1940s (“The Story of Fluoridation”). Incorporating fluoride in water acts as both a topical and systemic treatment; fluoridated water is in direct contact with teeth, otherwise known as the topical application, and it is systemic since it also becomes ingested into the body. But, in acting as a systemic treatment, it poses an actual risk that can cause further damage to individuals’ health. Ever since the implement of water fluoridation in public water systems in the mid 1900s, there has been an increase in fluoride toxicity, thus leading to an increase...
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...The city of Wichita has an important decision to make. This decision is vital to each and every person living in or around Wichita. It will affect many people and will adversely affect their health in many ways. Many people have been to a convenience store and purchased a bottle of water, or a restaurant where they ordered a glass of water but few people ever consider what’s in the water. If a customer were to order a glass of water at a restaurant they would expect a glass of clean unadulterated water. For example when you order a glass of tea, several questions are going to follow. “Sweet or Unsweet?”, “Would you like a lemon in your tea”. Almost each and every drink ordered at a restaurant would have a few basic questions with the exception of water. There is not a single question or modification that can or should be made to water. However, what if the waiter asked you, “Do you want some chemical in your water?” Many people would be shocked or even confused on how or what to answer. Still you have another group of people that would firmly say no, and those people may even wonder if they chose the right establishment to patronize. This is the decision that the city of Wichita is pondering. This decision is to decide whether or not to add the chemical, fluoride to the water supply. Fluoride is usually found naturally in low concentration in drinking water and foods. The concentration in seawater averages 1.3 parts per million (ppm). Fresh water supplies generally...
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...Opposition Opposition to community water fluoridation has existed since the practice was implemented (McLaren & McIntyre, 2011). Opponents often argue that water fluoridation can cause health problems. Adverse effects of over-exposure to fluoride include dental fluorosis, skeletal fluorosis, and toxicity. Dental fluorosis can range from mild white striations in the enamel to severe brown staining and pitting (Stoneman, 2014). Generally, communities with water fluoridation have a higher prevalence of dental fluorosis in comparison to communities that do not have fluoridated water (Stoneman, 2014). Skeletal fluorosis is a crippling disease caused by prolonged exposure of ≥ 10mg of fluoride per day for at least ten years, but it is extremely rare in North America and is not a public health concern in Canada (Stoneman, 2014). Opponents also argue that water fluoridation is expensive, harmful to the environment, and infringes on personal freedoms. The estimated cost of water fluoridation is $0.60 to $1.00 per person, per year (Rabb-Waytowich, 2009). Concerns related to the environmental impact of fluoride mostly stem from industrial pollution or accidents involving high volumes of fluoride. Lastly, opponents argue that water fluoridation interferes with their individual freedoms. Support Supporters often cite that water fluoridation for preventing tooth decay is supported by over 90 national and international government and health organizations, including Health Canada, the Canadian...
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...Essay: Fluoridation of Public Waters According to the CDC, public fluoridation of public water has been identified as one of the 10 greatest public health achievements. The first documented use of fluoridation of public water supply was in Michigan in1945. There are many reasons to add fluoride to the water supply, but the reasons appear to be cost of delivery and ease of delivery. Public water systems are maintained by local water municipalities throughout the United States. The federal government sets the recommended rate. (Center for Oral Health, 2011) When looked at in comparison with other modes of fluoride delivery, i.e. toothpaste, dentist application, and Rx supplements. Water fluoridation is the least costly. Studies as far back as the 1940’s have shown that communities with fluoridated water supplies have fewer individuals with caries than those without fluoridated water supplies. In studies conducted prior to 1980 which showed 50 percent less tooth decay in communities with fluoridated water vs. those with non-fluoridated water; it was inferred that the cost of averted disease has been found to exceed the cost to implement and maintain fluoridation.(Griffin, 2001) In a 2000 study conducted on the economic evaluation of community water fluoridation the authors found, that, based on the data available on the effectiveness and cost of fluoridation, caries increment and cost and longevity of dental restorations, that water fluoridation offers...
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...As mentioned in the textbook “Health Care Delivery in the United States” under the section “Public Health Every Day” we tend to not think about the affects of public health in our everyday life even though we are surround by it (Leviton, Rhodes & Change, 2012, p.104). After reading this section I realized that this past week from waking up until going to sleep, my daily habits are filled with activities that are associated with public health topics. Upon waking up and brushing my teeth, the water supply from the faucet has fluoride in it. The level of fluoride in the water of Denver, CO was established by the Center for Disease Control and the Colorado Department of Public Health and Environment to help prevent tooth decay and promote oral...
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...Campaigners say no to fluoride We’re all now acutely aware that our public water supply has a substance known as fluoride in it. Whether you’re aware of the reasons why or not, it’s also highly likely that you’re aware this is not a positive thing. Daily consumption of fluoride straight from our kitchen tap has been scientifically proven to contribute toward male infertility, early onset puberty and even brain conditions amongst other things. Despite rather disconcerting evidence against the use of fluoride, water treatment facilities continue to introduce it into our water supply. Campaigners in the borough of Bedford however have taken to the streets in a bid to fight against fluoridation. Clipboard carrying teams known as Fluoride Free Bedford have been spending time in their local high street in order to spread the message of fluoride and its associated dangers. Not only have they been spreading the word, they’ve also been asking shoppers and locals to sign their petition which calls for the council to put a stop to water fluoridation in their borough of Bedford once and for all. The campaigners, highlighted by a number of local papers, are becoming increasingly frustrated after the Bedford Borough Council voted in favour of ceasing to practice water fluoridation after Major David Hodgson put the proposal forward in 2011. Despite the success of the vote however, no action has ever been taken and Fluoride Free Bedford are not happy and to make matters worse, they now have...
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...radiation in the form of alpha, beta, and gamma rays. Some radioactive isotopes include: Carbon-11, Copper-64, Fluorine-18, and Oxygen-15. These isotopes have different properties and are used to detect and cure health issues through the use of radioactive pharmaceuticals such as PET scans and radiation therapy. PET scans, or Positron Emission Tomography scans, are used to determine what kind of diseases may reside in the body; this is done by introducing a positron- emitting radionuclide, which gathers in the target tissue. As this radionuclide decays it emits a positron, which combines with a nearby electron; this in turn results in the simultaneous emission of two identifiable gamma rays in opposite directions (Radioisotopes in Medicine, 2013). These gamma rays are then detected by the use of a PET camera. Some radioactive isotopes; such as Carbon-11, Nitrogen-13, Oxygen-15, Fluorine-18, and Copper-64, are used in PET scans as positron emitters. PET’s are used mostly in the field of oncology (the study of tumors and cancers) and most commonly use the isotope Fluorine-18 as the tracer. Fluorine-18 is most often used because of its half- life, which is approximately 110 minutes. This is certainly a lot longer than the half-lives of Carbon-11, Nitrogen-13, or Oxygen-15 which have half-lives of twenty, ten, and two minutes respectively. The long half-life of Fluorine-18, coupled with the fact that as it decays by emitting positrons with low positron energy and generates sharp...
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...However, not all single-replacement reactions which appear to work on paper occur in real life. This is seen with fluorine, chlorine, bromine, and iodine. These elements are called halogens and are found in group VII of the periodic table. Only the halogens on top of the column will replace halogens below. This is seen in this example where chlorine which is above iodine in the periodic table replaces it in this single replacement reaction: KI(aq) + Cl2(g) → KCl2(aq) + I(s). Here is an example of a reaction that will not occur: CaF2(s) + Br2(l) → CaBr2(s) + F2(g). In this reaction bromine cannot replace fluorine because bromine is below fluorine on the periodic table. Both fluorine and bromine, when reacting with an atom, gain an electron to form a negative ion. Fluorine is better at forming a negative ion then bromine in the reaction because fluorine is more electronegative than bromine (fluorine is the most electronegative element). Fluorine does a better job of attracting an incoming electron and thus becoming ionized than bromine because of the stronger pull of electrons to its nucleus. That is the reason why...
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...Sherrilyn Ling History of the Universe Lenny Tevlin October 5, 2015 6. Briefly describe the structure and size of an atom. How big is the nucleus in comparison to the entire atom? Atoms are extremely small; millions of atoms could fit end to end across a period at the end of a sentence. Protons and neutrons are found in the tiny nucleus at the center of the atom. The rest of the atom’s volume is made up of electrons, which surround the nucleus. The nucleus is very small compared to the atom as a whole, but it contains a majority of the atom’s mass. 7. What determines an atom’s atomic number? What determines its atomic mass number? Under what conditions are two atoms different isotopes of the same element? What is a molecule? The atomic number is the number of protons in a chemical element’s nucleus. The atomic mass number is the combined number of protons and neutrons in an atom. Isotopes occur when versions of an element have the same number of protons but a different number of neutrons. A molecule is formed when atoms of the same element combine. 8. What is electrical charge? Will an electron and a proton attract or repel each other? Will two elections attract or repel each other? Explain. Electrical charge is a fundamental property that describes how strongly an object will interact in electromagnetic fields. Protons and electrons attract each other, but two electrons repel. Protons have a positive charge and electrons have a negative charge; like charges repel...
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... electron configuration 1) Copper Cu 1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s1 Chromium Cr 1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1 Chlorine Cl 1s2, 2s2, 2p6, 3s2, 3p5 Neon Ne 1s2, 2s2, 2p6 Potassium k 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 Magnesium Mg 1s22, 2s2, 2p6, 3s2 2) Electronegativity Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used. Fluorine (the most electronegative element) is assigned a value of 4.0, and values range down to ceasium and francium which are the least electronegative at 0.7. As you go down a group, electronegativity decreases. (If it increases up to fluorine, it must decrease as you go down.) As you go across a period the electronegativity increases. 3) MgCl2 IONIC BOND 4) TYPES OF BONDS Primary; Ionic bonding Covalent bonding Metallic bonding Ionic bonding Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion. Secondary; Secondary bonds (also known as interparticle, intermolecular...
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...Chapter 8 Covalent Bonding and Molecular Structure Chapter 8: Covalent Molecular Structure Bonding and Chapter In Context In this chapter and the next, we examine chemical bonding in detail. We examined ionic bonding briefly in Chapter 2 and will do so in more detail in Chapter 11. We will also examine intermolecular forces in detail in Chapter 11. Here we will apply what you have learned about atomic structure (Chapter 6), electron configurations, and periodic trends (Chapter 7) to the chemical bonds formed between atoms and ions and the shapes of molecules and ions that contain covalent bonds. • 8-1 Biology: Molecular shape of enzymes specifically allow only certain reactions to occur. Drugs are developed that specifically fit into active sites in the enzyme to affect or even stop its action. Chapter 8 8.1 Interactions Between Particles: Coulomb’s Law 8.2 Covalent Bonding Basics 8.3 Lewis Structures 8.4 Bond Properties 8.5 Electron Distribution in Molecules 8.6 Valence-Shell Electron-Pair Repulsion Theory and Molecular Shape 8.7 Molecular Polarity Chapter Goals • Apply Coulomb’s Law. • Understand forces involved in covalent bonding. • Write Lewis symbols and Lewis structures. • Predict bond properties. • Understand charge distribution in molecules. • Use VSEPR theory. • Identify polar and nopolar species. Chapter 8 Covalent Bonding and Molecular Structure 8-2 8.1 Interactions Between Particles: Coulomb’s Law OWL Opening Exploration 8.1 Coulomb’s Law Matter is...
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...occupy higher energy levels. d) The element that would have the greatest first ionization energy would have to be Helium with a 2.37 kJ/mol first ionization energy. The element that would have the smallest first ionization energy would be Rubidium with ionization energy of 0.40 kJ/mol. Part 3 – Electron Affinity 12. The change of energy that happens as an electron is added to the outer energy level. Atoms that have a high affinity for electrons have a low electron affinity number (indicated by a low negative number). Atoms that have a low affinity for electrons have a high electron affinity value (indicated by a negative number close to zero, or a positive number) 14. a) The elements that are found at the main peaks of my graph are Fluorine, Chlorine, and Bromine. They are all found in the same group. They are all other non-metals. b) The elements that are found at the valleys of my graph are Boron, Aluminum, and Gallium. They are all found in the same group. Boron is a non-metal, and Aluminum and Gallium are poor metals. c) The similarities I see between this graph and the other previously constructed graphs are that the trends tend to be the same. The elements located at the valleys and the peaks of my graphs are all the same group and are all part of the same type of metal or non-metal. In some cases the elements can be different. 15. a) It would be a negative correlation, but yes. Generally speaking, electron affinity tends to increase as atomic radius decreases....
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...How can Sodium Fluoride Ion solve the issue “cavity” In this essay, I will explore about how sodium fluoride ion can be addressed to one of the most common health issues in the world “cavity” by investigating the properties of sodium fluoride ion and how those properties of sodium fluoride ion are related to addressing this issue. Sodium Fluoride ion is an ionized combustion of non-metal atom Fluorine and alkaline metal sodium as you can notice from its name, and its scientific equation is NaF. In nature a singular fluorine cannot be easily found, according to “How does the fluoride in toothpaste prevent cavities? Is there any kind of 'natural' fluoride protection or is it only in artificial compounds?” by “SCIENTIFIC AMERICAN” “Fluorine, the 13th most abundant element in the earth's crust, is never encountered in its free...
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