Study "Chemistry / Elements" Essays 1-55

12. . .
X Filters 

Evolution of Chemistry Research Paper

… org, 2013). In following tests, it was found to cause the flame to burn more intensely and to keep the mouse alive longer (acs.org, 2013).

It's also vital to bear in mind that Priestly was a pneumatic chemist; there were… [read more]


Chemistry of Living Things Essay

… Chemistry of Living Things

Basic chemistry dictates that matter refers to anything which occupies space and has mass. Elements are the smallest form of matter which cannot be broken down further to a simpler form. Examples are aluminum and iron.… [read more]


Nuclear Chemistry Term Paper

… ¶ … nuclear chemistry, including the history of its development, a brief examination of certain key reaction that are used and examined in the field, and an assessment of nuclear chemistry's value to chemistry as a whole. Nuclear chemistry deals… [read more]


Physical Chemistry Notes Website: Pomona University "Moldata Thesis

… Physical Chemistry Notes

Website: Pomona University "MolData:" Physical Chemistry Resources

No hard data contained on this website, but links provided to any different databases and tables with an abundance of technical information pertaining to atoms and physical chemistry

Contains links… [read more]


Symmetry in Inorganic Chemistry Molecules Term Paper

… The overall molecule responds to symmetry operations in a manner that is captured by the behavior of the particular group to which the molecule belongs, individual atoms, bonds, atomic orbitals and any other component of the overall molecule may respond… [read more]


Chemistry at Work. Every Facet Term Paper

… Of CO and not to the first R. Or Ar (Morrison & Boyd, 1983, pp. 734-737).

Carboxylic acids are also important. Vinegar, used in cooking, is the simplest organic acid. Its formula is CH3COOH -- acetic acid. The functional group COOH is the carboxylic acid group. It combines a carbonyl group (C=O) with the OH group attached to the carbonyl carbon atom (Morrison & Boyd, 1983, p. 755).

Esters are derived from carboxylic acids. The H. In the OH part of the acid (COOH) is replaced by an R. Or Ar group. The generic formula for esters is therefore, R (Ar)-COO-R'(Ar'). The prime (') indicates that the R. groups or Ar groups need not be similar (Morrison & Boyd, 1983, p. 830).

The last functional group is a derivative of ammonia NH3 that is used in smelling salts and glass cleaning solutions. An alkyl group or aryl group replaces one of the hydrogen atoms in ammonia. The resultant compound is an amine. Methylamine CH3NH2 is the simplest example (Morrison & Boyd, 1983, p. 878).

Thus Chemistry helps life -- intrinsically and extrinsically. Chemical processes are observed at macroscopic levels and microscopic levels. They are man made or have evolved with nature. The salient point to remember in the formation of compounds (everything else flows from there) that drives chemical processes is the need to complete the valence or the atomic shell -- each element's inherent instability. Inorganic and organic chemistry is the results of variable approaches to solving the instability. This then results in the formation of stable compounds the world we live in and the universe at large need to survive.

References

Hachiya, M. (1945). The Hiroshima/Nagasaki Legacy. Retrieved January 26, 2003, at http://nuketesting.enviroweb.org/hew/Japan/Hirosh.html

Aquatext Online (2000). Composition of Air. Retrieved January 26, 2003, at http://www.aquatext.com/tables/air.htm

WebElements (2003). WebElementsTM Periodic table (professional edition). Retrieved January 26, 2003, at http://www.webelements.com/

Lee, M. (1999) Covalent Bonds. Retrieved January 26, 2003, at http://207.10.97.102/chemzone/lessons/03bonding/mleebonding/covalent_bonds.htm

Lee, M. (1999) Ionic Bonds. Retrieved January 26, 2003, at http://207.10.97.102/chemzone/lessons/03bonding/mleebonding/ionic_bonds.htm

Morris, R.T. And Boyd, N.B. (1983). Organic Chemistry. 4th Ed. Boston: Allyn and Bacon, Inc.… [read more]


Integrated Science and Periodic Table Essay

… Metals from the left side of the periodic table have the tendency of losing electrons in order to stabilize itself. Because the ionization energy from left to right increases, the lower the ionization energy, the easier it will be for these metals to lose their valance electrons, making it favorable for them to combine and react with elements from the right side of the periodic table (Chang 2010). These elements are the opposite of the left side elements. These ionization energies are much higher, therefore it is easier for them to gain an electron from another element to form a compound, than it is for these elements to give a valance electron up. These right-sided elements are called non-metals. However, these non-metals are further broken up into categories. Elements in group VII are called halides or salts because of their tendency to react with the elements from group I in order to form salt ionic compounds (Chang 2010). Examples of this include sodium fluoride (Na+ and F-) and sodium chloride (Na+ and Cl-) which is table salt. Noble gases, which are the elements in the final group, have complete valence shells, so they do not pair well with the left-sided elements, although they do belong to the non-metals group (Chang 2010). This is also due to their high ionization energies which make it impossible to break these elements apart or to give or take an electron.

Octets are formed when an atom has a full valence shell. That is, an element is more stable if the number of electrons surrounding the nucleus has a sum of eight (Chang 2010). This is what covalent bonds are all about. Nonmetals from the right side of the periodic table react with nonmetals from the same right side because these elements have extremely high ionization energies, therefore it is more efficient for the element to share an electron with another element from the same side instead of giving an electron or gaining an electron from the elements in the first group on the left side of the periodic table (Chang 2010). It takes a lot more energy than it does to just share the electrons. Because these elements need only one or two more electrons to fill up their valence shell, they combine and share the missing electron with each other. A perfect example of this is water. Hydrogen, which belongs to both the left side and the right side of the periodic table because of its similar characteristics with both types of elements, forms a covalent bond with oxygen to form the covalent molecule, H2O. Oxygen needs two more electrons to complete its shell and have an octet, so it shares the electron that hydrogen has. Because oxygen needs two more electrons, and hydrogen only has one, it needs another hydrogen atom to become a stable molecule. Another example is hydrogen sulfide (Chang…… [read more]


Philosophy of Chemistry Essay

… Chemistry has been originally viewed by the philosopher as having been reduced to mere physics thereby holding no interest fundamentally however, those misconceptions are presently being examined and reflected upon. Models and methodology of chemistry research are also being critically examined as well as is the realism in relation to chemistry and the scientific terms utilized. Molecular structure is also undergoing critical analysis and as indicated in the work of Scerri molecular structure is held as a mere metaphor with no objective reality at the quantum mechanical level. These are only some of the aspects of chemistry that are presently being questioned by philosopher and chemists alike in the search for meaning behind the philosophy of chemistry in today's science community.

Bibliography

Scerri, ER (1997) Philosophy of Chemistry -- A New Interdisciplinary Field?. Retrieved from: http://www.chem.ucla.edu/dept/Faculty/scerri/pdf/poc_=JCE_article.pdf

Hoffmann, R. The Same and Not the Same; Columbia University Press: New York, 1995. Knight, D. Ideas in Chemistry, Rutgers University Press: New Brunswick, NJ, 1992. Nye, M.J. From Chemical Philosophy to Theoretical Chemistry; University of California Press: Berkeley, 1993. Laszlo, P. La Parole des Choses; Collection Savoir-Science: Paris, 1993. Hoffmann, R.; Laszlo, P. Angew. Chem., Int. Ed. Engl. 1991, 30, 1 -- 16

Scerri, ER and McIntyre, L (2000) The Case for the Philosophy of Chemistry. Retrieved from: http://philsci-archive.pitt.edu/256/1/Case_for_poc.pdf

Schummer, J. (2006) Philosophy of Chemistry. in: Donald M. Borchert (ed.), Encyclopedia of Philosophy, Second Edition,…… [read more]


Proton and Carbon NMR Research Paper

… Proton and Carbon NMR

In chemistry one of the most common issues is constant change. This is based on chemical properties continually transforming into different states. In some cases, these shifts are visible to naked eye. While at other times,… [read more]


Green Chemistry Lesson Plan Lab Report

… Green Chemistry Lesson Plan

Green Chemistry - Lesson Plan

Lesson plan:

It's not easy being green: The 12 principles of green chemistry

Educational goal: To understand how the green principles of chemistry affect students' daily lives and the products they use

The 12 principles of green chemistry are extremely relevant in terms of the ways that they affect the industrial development of new products. The 12 principles counsel that it is advisable to avoid waste; to incorporate as many as possible of the materials involved in the production into the final product; that manufacturers should strive to create nontoxic synthetic products; that chemical products should be designed to realize their intended function while minimizing their toxicity; that there should be a minimization of auxiliary substances used in production; that the environmental and economic impact of the chemical product should be minimized; that raw materials should be renewable whenever possible; that unnecessary derivation from other sources should be minimized; that production should emphasize catalytic reagents to stoichiometric reagents; that products should be designed to degenerate so as not to add to the waste or toxicity in the environment; that products should be monitored so as not to become hazardous; and products should be designed to minimize the potential for accidents (12 principles of green chemistry, 2011, ACS).

Teacher background information: The standards from Massachusetts Science Curriculum Frameworks state that students in grades 6-8 should be able to:

Formulate a testable hypothesis using the scientific method and design and conduct a scientifically-valid experiment with variables that can be changed, controlled, and measured.

Select appropriate tools and technology for an experiment and make quantitative observations about an experiment.

Draw conclusions and present and explain data and findings using multiple representations (such as tables, graphs, mathematical and physical models, and demonstrations to the class using numbers as well as words) and use science and technology terminology.

"Offer explanations of procedures, and critique and revise them as necessary" (Massachusetts curriculum frameworks, 2011, Massachusetts Education).

Safety information: Most of the out-of-class work will…… [read more]


Garage Chemistry and Do-It-Yourself Science Labs Essay

… Garage Chemistry and Do-It-Yourself Science Labs

It is a litigious world humans have created, and the lawyers rule it. The history of almost all commercially available products can be traced from a distant heyday of free thought and free will… [read more]


Mercury Is Element Number 80 Thesis

… Mercury is element number 80 and is symbolized Hg. It appears on the periodic table in the far-right column of transition metals, right next to the poor metals. With only two electrons in its outer shell, it is incredibly reactive and volatile. There are also several radioactive isotopes of mercury, several of which are highly unstable: HG 197 has a half-life that is measured in hours, and HG 206 has a half life of less than nine minutes. The most unique thing about mercury is that it is the only metal that is liquid at room temperature. it's melting -- or freezing -- point is a chilly -38.9 degrees Celsius (roughly -38.02 degrees Fahrenheit). It is also a very poor conductor of heat, which is one of the reasons it is so useful in thermometers -- it expands and contracts over a wide range in response to temperature changes.

Mercury is also very good at conducting electricity, and is often used in batteries. It is also very reactive with other metals, and can be used to make amalgams (alloys) with other metals. It is so…… [read more]


Chemistry and Photosynthesis Chemically Speaking Term Paper

… chemistry and PHOTOSYNTHESIS

Chemically speaking, photosynthesis is the utilization of sunlight by plants for the conversion of carbon dioxide into organic matter. In green plants like trees, shrubs, flowers and conifers, the overall chemical reaction may be represented by the… [read more]


Metallic Element Erbium: Term Paper

… Metallic Element Erbium

Erbium: The Metal and Its Uses

This paper explores the metallic element erbium, which prior to the use of fiber optic communication systems and "Wi Fi" communications received little attention. Considered a rare element, erbium while typically… [read more]


Abundant Elements That Occur Term Paper

… Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen, with a typical ratio of 1:2:1, respectively; they tend to be polar; they are broken down during cellular respiration; and they provide most of the body's energy. Proteins, also organic compounds, consist of hydrogen, oxygen, carbon, and nitrogen atoms; they include chains of amino acids, which in turn form strings of polypeptides; they are usually soluble in water, salt solutions, or in alcohol; they have a coiled structure; and they are the major structural and functional material of body cells. Lipids are fatty compounds made of carbon, hydrogen, and oxygen, with an abundance of carbon-hydrogen bonds; they are not water soluble; and their purpose is to store energy. Nucleic acids are complex organic compounds that store important information in cells; they contain phosphorous, carbon, oxygen, hydrogen, and nitrogen; and they are mildly acidic. DNA and RNA are the most important types…… [read more]


Inorganic Chemistry Linear Sp Carbon Term Paper

… Additionally, when the polyenes are end-capped with organic or organometallic groups, the instability becomes likewise proportionately affected. It was cited from previous studies that shorter interchain distances are favorable for achieving stability, and the addition of bulky terminating groups do… [read more]


Chemistry Problems There Is a Wealth Chapter

… Chemistry Problems

There is a wealth of information that can be provided in the formatting of discussing various compounds, like that of NH3. For ammonia, the Lewis Structure provides a clear glimpse of where the nitrogen bonds with hydrogen. This model clearly shows that nitrogen still has a lone pair of atoms which causes the atom to have a trigonal pyramid shape.

This triangular shape is also present in the space filling model. The space filling model presents the triangular shape in a more realistic 3D view that clearly shows the close bonds between the hydrogen and nitrogen in the bottom three corners of the ammonia atom.

Again, the unshared electron pair makes a triangular shape in the ball and stick model, however, the degree of the bonds can be more clearly represented being that they are further spread apart compared to the space filling model. Like the Lewis structure, it can clearly be seen that it is a single bond between the nitrogen and its three hydrogen particles.

Finally, in the geometric sketch, the degree of the bond connections is seen in greater detail. Here, the ammonia atom clearly has a very definite triangular shape, with 106 degree bond angle where the hydrogen…… [read more]


Ionic and Covalent Bonds Chemical Essay

… Ionic and Covalent Bonds

Chemical bonds are formed when there is an attraction between atoms that allows chemical substances containing more than two atoms form. The two forms of chemical bonding are ionic bonding and covalent bonding. Furthermore, ionic bonds and covalent bonds can be combined to form mixtures and compounds.

Ionic and covalent bonds form when two or more elements are bonded together. Elements are pure substances that are comprised of one atom. The elements can be found on the periodic table, arranged by their atomic number. There are 117 elements that have been discovered to date; 94 of these elements are found to be naturally occurring while the remaining 22 elements are artificial. Substances that are formed by ionic and covalent bonds can be further combined to form mixtures and/or compounds. A mixture is a heterogeneous form of matter composed of varying proportions of molecules and atoms. A mixture can be any combination of substances. These substances that comprise a mixture keep their individual and characteristic properties; these substances can be easily separated from the mixture. Separation of these substances can be achieved through dialysis, chromatography, or electrophoresis. Dialysis is the separation of molecules in a solution in which the molecules diffuse through a semi-permeable membrane. Chromatography separates molecules based upon differing partitioning behaviors that occur between a mobile and stationary phase. Electrophoresis separates substances based upon the rate of their movement in a colloidal suspension when introduced to an electric field (Decelles, 2001).

Compounds are pure substances that are made up of two or more elements. Whereas a mixture is a heterogeneous form of matter, a compound is a homogeneous form of matter where the elements are present in fixed proportions. The elements that make up a compound do not retain their individual properties and large amounts of energy are required to separate a compound into its separate parts. Compounds are naturally formed to provide elemental stability. This stability is dependent on the number of electrons found in the outermost energy level of an atom.

Ionic bonds are formed when atoms link together because of the attraction of ions that have opposing charges. Ionic bonding requires that electrons completely transfer from one of the bonding atoms to the other. Electrostatic forces allow for these electrons to be attracted to each other. When an atom loses an electron, this atom will reduce in size. Inversely, when an atom gains an electron, the receiving atom will grow in…… [read more]


Bonds and Compounds Essay

… Chemical Bonds: Ionic and Covalent Bonding

A chemical bond is an attraction between atoms that lets chemical substances that contain two or more atoms. Two forms of chemical bonding are ionic bonding and covalent bonding. Additionally, ionic and covalent bonds can be combined to form mixtures and compounds.

Ionic and covalent bonds are formed through the bonding of two or more elements. An element is a pure substance composed of a single atom. There are currently 117 known elements with 94 elements occurring naturally and 22 artificial elements. The properties and names of all known elements can be found on the Periodic Table.

Ionic bonded and covalent bonded substances can be combined to create either a mixture or a compound. A mixture is a heterogeneous form of matter that is composed of variable proportions of molecules and atoms. The properties of a mixture include the variability of the composition that means that a mixture can be any combination of substances. In a mixture, the components that make up that mixture retain their individual characteristic properties and the components of said mixture are easily separated. Mixtures can be separated through various forms including dialysis, chromatography, and electrophoresis. In biochemistry, dialysis is the separation of molecules in a solution based on their differing rates of diffusion through a semi-permeable membrane. Chromatography is a separation method that is based on the differences in the partitioning behavior between a mobile phase and a stationary phase. Electrophoresis is the separation of substances based on the rate of movement of each component in a colloidal suspension when under the influence of an electric field.

Compounds are pure substances that are composed of two or more elements. Unlike a mixture, a compound is a homogeneous form a matter in which the elements are present in fixed proportions. Additionally, components that comprise a compound do not retain their individual properties and large inputs of energy are required to separate a compound into its separate components. Compounds are formed naturally to provide elemental stability; stability is determined by the number of electrons present in the outermost energy level of an atom.

Ionic bonds are formed when atoms link together due to the attraction of ions with opposing charges. In ionic bonding, electrons are completely transferred from one of the bonding atoms to another atom. These electrons are…… [read more]


Chemistry Term Paper

… To obtain a complete force map the microscope needed to be highly stable, both mechanically and thermally, to ensure that both the tip of the AFM and the molecule remained unaltered during the more than 20 hours of data acquisition." (IBM)

This is a key discovery because the atomic structure that is now available to all scientists can be considered to be the backbone of the atomic world. "Scanning probe techniques offer amazing potential for prototyping complex functional structures and for tailoring and studying their electronic and chemical properties on the atomic scale." (IBM)

The remarkable thing about this advance is that it comes just a few months after another astonishing discovery. "The team's current publication follows on the heels of another experiment published just two months ago in the June 12 issue of Science (Volume 324, Issue 5933, pp. 1428-1431) where IBM scientists measured the charge states of atoms using an AFM. These breakthroughs will open new possibilities for investigating how charge transmits through molecules or molecular networks." (IBM) Most people in the world will not have a clue what this combination of discoveries entail. What it translates into is completely new nanotechnology.

That is because, when scientists have a good grasp of the charge distribution at the atomic scale, they can translate that information into building even smaller, faster and completely energy-efficient computer components. These breakthroughs will literally make many of today's computer parts like processors and memory devices completely obsolete. Of course, IBM has a vision of an all IBM planet that is interconnected so the potential financial implications for the company could be significant. "Scientists have been striving to 'see' and manipulate atoms… [read more]


Avogadro Chemists Use Avogadro's Number Term Paper

… Avogadro

Chemists use Avogadro's Number on a daily basis and it is therefore necessary to not only know and understand what the number signifies, but also to know who created it, why it was created, and of what use it is in today's chemical society.

The name "Avogadro's Number" is just an honorary name attached to the calculated value of the number of atoms, molecules, etc. In a gram mole of any chemical substance. Of course if we used some other mass unit for the mole such as "pound mole," the "number" would be different than 6.022 x 1023."(Furtsch)

The title honors Amedeo Avogadro, an eighteenth century scientist born in Turin, Italy on August 9, 1776. His family was comprised of successful lawyers, and he followed the family's tradition by graduating in ecclesiastical law.

Lorenzo Romano Amedeo Carlo Avogadro, known as Amedeo Avogadro, one of the many creative Italians that have enriched our lives, was born in 1776 - a memorable date hitherto for other reasons. Possibly of aristocratic descent, he was a lawyer until he decided to devote himself to one of his other interests: in his late twenties he was appointed to the first chair in mathematical physics in Italy, at L' Universita' di Torino." (Avogadro)

His interest in law never waned but was supplanted by his interest in natural science. This interest compelled him to attend private lessons in both mathematics and physics. Following and intense period of study, he wrote a hypothesis that contributed several facets to the science community.

Avogadro was the first to publish (in 1811) the idea that elements could exist as…… [read more]


Unaware Term Paper

… These are accomplished by the chemical processes applied by the forensic scientists, techniques like employment of molecules such as nucleic acids and proteins.

Another event specific to the use of chemistry to provide evidence is explosion. It may occur deliberately or accidentally during domestic, commercial, criminal or terrorist cases. Identifying and tracing the capacity of materials from the explosive devices is essential to know the cause of the explosion.

The terrorist event in 1993 in the underground parking lot of the World Trade Center was an instance where chemistry helped in identifying the materials used. The bomb was created using various chemicals that was exploited to produce chain reaction. The investigators found out that a gel of urea nitrate was used when they analyzed the debris in the parking. A high level of urea and nitric acids were found.

The application of chemistry is very important in arson and explosives investigation. The proficiency in conducting chemical examination aid in the process of determining the causes and producing evidences through the scientific analysis and implementation of chemistry. Any material, debris, and residues in any investigation are important for chemical testing to build facts about a case. The role of chemistry and the duties of the forensic analyst go hand in aiding mysteries and unknown causes of a particular crime. It is not only in the resolution of a case that forensic chemistry plays a vital role. It also helps in reducing the potentiality of crime.

Tracing evidences with the application of various chemical examinations is a big factor that shows and provides elements of a particular crime. Without chemistry, many crimes would still have been unresolved today. As how chemistry is important in our daily tasks, it is of the same importance in many professions. We live in a world of various elements. Understanding and knowing their importance is an essential part in achieving many of our tasks. As in the investigation of crimes, the ability of having a good knowledge in the field of chemistry is one of the basic requirements to provide better service in the protection of every citizen and in exhibiting evidences of crimes.

Bibliography

Borer, Keith. Forensic Chemistry.

Keith Borer Consultants Limited. 22 March 2003. http://www.borer.demon.co.uk/chemistry.htm

The Role of Forensic Scientist in Detection of Crime. http://assampolice.com/art2.htm

BSC Forensic Science.

2002. University of Central Lancanshire. 22 March 2003. http://www.uclan.ac.uk/facs/science/forensic/courses/bscforensicscience.htm

Chemistry and BioChemistry.

Ohio University. 22 March 2003. http://main.chem.ohiou.edu/undergraduate/forensic.html#What

Forensic Chemistry. 21 March 2003. http://www.westchestergov.com/labsresearch/labs/forensicandtox/forensic/Chemistry/Forchemmaindr.htm… [read more]


Chemistry Problems Acids and Bases Chapter

… Chemistry Problems

Copper (II) hydroxide (used as a pigment) is insoluble in water

BaBr2 (used to make photographic compounds) is soluble in water

Silver carbonate (used as a laboratory reagent) is soluble in water

Pb3(PO4)2 (used as a stabilizing agent in plastics) is insoluble in water

Upon colliding with a water molecule (H2O), the hydrofluoric acid molecule (HF), an H+ is available to transfer to the water molecule. This creates a hydronium ion (H3O+) along with a flouride ion (F-), which is often formed in reverse when it reacts with hydronium ions that attach and pull H+ ions as it tries to reform HF and H2O. Both sets of reactions, regular and reverse, occur simultaneously and continuously within the solution until they reach an equal rate, where there are no additional changes to the numbers of HF, H2O, F-, or H3O+.

a. Oxyacid

b. Polyatomic ionic compound

c. Polyatomic Ionic compound

d. Binary Ionic compound

e. Binary acid

f. binary Ionic compound

g. Binary Covalent compound

59. a. Strong Acid

b. Weak Base

c. Strong Base

d. Weak…… [read more]


Surface Plasmon Resonance-Based Biosensors Research Proposal

… ¶ … Plasmon Resonance-Based Sensors

Surface Plasmon Resonance-Based Biosensors

Surface plasmon resonance (SPR) was first observed in 1902 by Wood and this physical phenomenon has since begun to be used in multiple applications. Modern detectors now use the phenomenon to detect sub-monomolecular coverage. Since Wood came across the phenomenon, it has been perfected by Lord Rayleigh, Fano, Krestchmann and Raether. Actual sensors first came into use in 1983 by Liedberg. A good conceptual example is a polarized light being shone through a prism onto a sensor chip assembly with a film of thin metal on top. The shining of the light incites surface plasmons into becoming active and this phenomenon can then be measured. A wave-like oscillation of free electrons is induced and the intensity of the light is reduced in the process. The angle at which the maximum amount of refraction loss occurs is called the resonance angle [1].

Applications

Surface plasmon resonance can be used to determine the concentration of an analyte in a sample during a quantitative analysis session. The analysis involves a calibration curve whereby a response over time to an SPR series is plotted on a graph in the form of a curve. The amount of data points (dilutions) can range from 10 times to 100 or even 1000 iterations. The results of this analysis will depend a lot on the sample size [1].

The most significant benefit of using SPR detection is being able to determine the kinetics of bio-molecular reactions. The interactions of an analyte and a ligand immobilized on the sensor surface can be ascertained using SPR techniques and technology. Assessing and analyzing the process and results of such experiments is not terribly complex or beyond most people's understanding. It is enough to know that an optical method is used to measure the refractive index within proximity of a sensor surface [1].

History

Biosensor as a term…… [read more]


NMR Spectra Nuclear Magnetic Resonance Research Paper

… Carbon 13 (13C) is not naturally abundant but provides a spin state of 1/2 or -1/2 and gives a NMR signal. NMR spectroscopy of 13C observes the skeleton of an organic molecule and allows determination of the chemical shift for… [read more]


Heat Capacity Research Paper

… Heat capacity, C of any given system is also noted to be the ratio of the heat that can either be added or effectively withdrawn from the given system in order to give rise to the resultant temperature.

C =… [read more]


Reduction Oxidation Redox Signaling in Wound Healing Research Paper

… Redox

Reduction-Oxidation (Redox) Reactions and Signaling at Wound Sites: Implications for Healing

Wounds are a natural if not especially pleasant feature of life. All living organisms will experience some sort of unwanted damage to their outer layers potentially due to… [read more]


Underground Directed by Emir Kusturica or the Periodic Table by Primo Levi Essay

… ¶ … Underground" directed by Emir Kusturica, or "The Periodic Table" by Primo Levi

The Second World War has been the scene of numerous horrible events, but the Holocaust is definitely the most shocking affair from the era. Because of… [read more]


Lithium Transition Metal Oxides as Battery Cathode Article Review

… Lithium Transition Metal Oxides as Battery Cathode

"Although the basics of electricity were established in 600 B.C. By the Greek philosopher

Thales of Miletus and then refined by scientist William Gilbert of England in 1600,

the first battery actually dates… [read more]


Oxidation-Reduction Series of Chemical Reactions Thesis

… Oxidation-reduction-reactions are a series of chemical reactions characterized by electron transfer from one molecular species to another (Kotz, Treichel, & Townsend 141). Specifically, oxidation describes the loss of electrons, while reduction refers to the gain of electrons (Kotz, Treichel, & Townsend 142). The molecular species which removes, or accepts, electrons during an oxidation-reduction-reaction is known as an oxidizing agent, or an electron acceptor (Kotz, Treichel, & Townsend 142). Conversely, molecules which donate electrons are termed reducing agents, or electron donors (Kotz, Treichel, & Townsend 142).

While oxidizing agents frequently contain oxygen, its presence is not a strict requirement for oxidation (Kotz, Treichel, & Townsend 141-143). Oxidizing molecules usually possess a high electronegativity, resulting in a strong attraction toward electrons (Kotz, Treichel, & Townsend 142). In addition to oxygen, the halogens fluorine, chlorine and bromine are common oxidizers that are strongly electronegative (Kotz, Treichel, & Townsend 141-143). In the case of the browning apple, however, the oxidizer is the oxygen present within the air (Nicolas et al.).

Reducing agents are molecular species which reduce other molecules, i.e. they donate electrons to another molecule (Kotz, Treichel, & Townsend 142). Reducing agents tend to be extremely varied and often highly electropositive (Kotz, Treichel, & Townsend 142-143). The high electropositivity accounts for a reducing agents predilection to donate electrons.

The browning of an apple occurs when the skin is broken and cell walls of the apple are compromised (Nicolas et al.). Ruptured cell walls allow the cellular contents to be exposed to the oxygen present within the air. In apples, an enzyme known as polyphenol oxidase facilitates the oxidation process (Nicolas et al.). Polyphenol oxidase, also known as tyrosinase, is an enzymatic protein found within the chloroplast of the apple cell (Nicolas et al.). Polyphenol oxidases function to drive o-hydroxylation of monophenolic compounds to produce o-diphenols and further catalyze the oxidative conversion of o-diphenols to o-quinones (Nicolas et al.). When…… [read more]


Laidler, Keith James. The World of Physical Thesis

… Laidler, Keith James. The World of Physical Chemistry. New York: Oxford University Press,

For many of us, chemistry is a subject in school that 'feels' as if it has always existed because of its apparent certainty regarding the natural world. The World of Physical Chemistry by Keith James Laidler illustrates that this is not the case by highlighting development of chemistry as a discipline. The creation of chemistry as a subject involved a process of discovery that existed in dialogue with history, personalities, and politics.

Chemistry is distinct as a scientific study because it is more concerned with the properties of individual substances, in contrast to physics' concern with general properties of matter (Laidler 5). It is a vast field, spanning the breadth of simple and quantum mechanics, spectroscopy, electrochemistry, colloid and surface chemistry. Laidler begins with how the ancient Greeks like Aristotle understood the atomic nature of matter, Newton and Galileo, as well as the First and Second Laws of Thermodynamics and ends with discussing Brownian motion and the achievements of Niels Bohr.

His book takes us on a tour of the biographies as well as the theories of major…… [read more]


Temperature and Heat Term Paper

… Temperature and Heat

Heat affects the temperature of the human body, water, land, atmosphere, and other structures of the earth. This is because the universe is made up of matter and energy. Matter is made up of atoms and group… [read more]


History of Atomic Theory Term Paper

… History Of Atomic Theory

Atomic theory is one of the most important theories developed in time in the field of physics and chemistry. The theory analyzes the nature of matter, stating that matter is composed of small units called atoms. Atomic theory formed since antiquity and was constantly improved since by the works of scientists.

Initially the theory of matter formed of atoms was approached in a more philosophical way, the scientific part of the theory being developed later in the 19th century. Greek antiques were the first to claim that matter was composed of indivisible units, but their approach was not based on experiment as it was rather a philosophical attempt to explain the universe. The Greek word atomos means indivisible and the theory of atoms was clearly defining that matter was composed of units obtained once you divide matter until no further division is possible, as presented by the Greek philosophers Leucippus and Democritus (History of atomic theory). Some understandings of Aristotle claim that the great philosopher himself allowed the idea that there is a minima in natural things. (Ancient Atomism)

Atomic theory was further analyzed and developed beginning with the 19th century, when John Dalton analyzed more closely the theory of atoms and presented the first results about the nature of atoms. He made a great contribution to the theory as he argued that atoms of one element are identical among each other, but that they are not identical with atoms of a different element. He also argued that combined atoms of different elements can create more complex substances, called chemical compounds (History of atomic theory). Comparing to the Greek theory, Dalton's was focused on the properties of substance and not its form. Dalton's conclusions proved to be correct and although his theory was further developed, he set the basis…… [read more]


MRI's Magnetic Resonance Imaging Term Paper

… However, some people must take some kind of sedation in order to cope with the MRI environment, which in addition to being a very confining space, is quite noisy. The noise is also unsettling to some patients.

A more serious… [read more]


Entropy Indeed, Entropy Governs Life Term Paper

… In understanding this one must recognize the concept of activation energy. (Clymer, 2002) This is a barrier to spontaneous conversion of reactants to products. Temperature, concentration and the use of catalysts often lower the activation energy. For example, a mixture of hydrogen and oxygen, even in 2:1 molar proportions will not form water spontaneously. The activation barrier has to be overcome by means of a spark, which causes an explosive reaction, thus forming water. A barrier to spontaneous energy dispersal does not mean that the law of entropy is defeated. Both laws of nature are sacrosanct.

To prove this, one might consider the phenomenon of photosynthesis. The leaf captures a very minute percentage of the sun's energy. This energy is dispersed throughout the leaf where food is prepared using carbon dioxide releasing water and oxygen. Some of the energy is also used to build food molecules (chloroplasts). This reconstituting of energy is against the law of spontaneous dispersal. This does not however, defeat the entropy laws. Photosynthesis is a naturally occurring process. Which means the overall entropy change should be positive. In photosynthesis, the overall energy dispersed is more than twice that which is used in recreating food molecules.

Another similar example can be seen in the workings of the mammalian body. The energy supplied from the outside in the form of food combined with the air we breathe is then converted into energy. This concentrated form of energy is dispersed throughout the body, the circulatory system and governed by the central nervous system. This energy dispersal and the processes of metabolism allow our bodies to remain at a constant temperature. Entropy is therefore governed by an energy gradient and dispersed from a high-energy point to a low energy point. This is necessary as is the spontaneity. Consider if the flow of energy was reversed and energy flowed from a lower to higher gradient with negative entropy changes. The move towards equilibrium would be defeated and life would cease to exist.

In identifying entropy changes along an energy gradient, one must identify a gap in the description of the Second Law. Namely, that this law does not indicate the path that energy dispersal takes, assuming that there are more than one available path. This gives rise to the notion of maximum entropy. (EntropyLaw, 2004) And it indicates that the path of maximum entropy is associated with the path of minimum gradient. To explain this, consider an airtight box at a higher temperature than the surroundings. Here the energy dispersal takes place through conduction across the walls of the box. If a door were cut into the box, maximal energy dispersal would take place along the path through the door or the path with the minimum energy gradient.

Entropy is very important. It governs every physical, chemical and biological aspect of life.

Bibliography

Atkins, P.W., and Julio De Paula. Physical Chemistry. 7th ed. New York: W.H. Freeman, 2002.

Clymer, Jeffrey. Arrhenius Calculation. 2002. Nuvox.net. Available:

http://members.nuvox.net/~on.jwclymer/arr.html. July 1, 2004.

EntropyLaw. The… [read more]


Admissions Essay Plus a Letter of Recommendation Essay

… ¶ … mom and I huddled in the corner when the police came. They banged on the door, shouting for my father. How did I get here? Why was my family running from the law? My dad had simply joined… [read more]


How Aspirin Is Prepared in the Lab Lab Report

… 2 grams of the salicylic acid is scooped into the tray and the mass of salicylic acid is recorded. The salicylic acid is then transferred to a 125-ml Erlenmeyer flask. Place 4 ml of acetic anhydride into the Erlenmeyer flask, mix and record the volume of acetic anhydride added. Add 5 drops of concentrated sulfuric acid / The salicylic acid should completely dissolve and result in a clear mixture. Go on swirling it. Place 1-2 ml chilled RO/DI water to the flask from a 10-ml graduated cylinder to decompose unreacted acetic anhydride. Mix and swirl with every addition of water. Set up you're your vacuum filtration apparatus. Add now 25 ml chilled RO/DI water to the reaction mix in the flask. Break lumps with a glass stirring rod. Weigh and record the mass of the filter paper. On the Buchner funner, moisten it with 1-2 ml of the RO/DI water. Turn on the aspirator so the moisture in the tunnel would go into the filter paper and seal it to the funnel. Swirling the mixture, pour it into the funnel at the center of the filter paper. With the aspirator on, rinse the aspirin with 15 ml of the chilled RO/DI water and keep it on for 10 minutes to drain the aspirin as much as possible. Then remove the clamp from the tubing to release. Transfer the filter paper and crystals into a weighed watch glass and store until completely dry.

4. Conclusion

This experiment shows that aspirin can be prepared from a mix of salicylic acid and acetic anhydride with salicylic acid as the limiting reactant. As plain salicylic acid, it irritates the stomach. But when hydrolyzed, it is less irritating and beneficial.

BIBLIOGRAPHY

CSUS. Synthesis of aspirin. Department of Chemistry: California State University, 2014.

Retrieved on October 28, 2014 from http://www.chem.csustan.edu/consumer/aspirincons/aspirincons.htm

Smith, K. .S. Preparation of Acetylsalicylic acid. Department of Chemistry: Michigan

Technological University, n.d. Retrieved on October 28, 2014 from http://www.chemistry.mtu.edu/kmsmith/syp/Student/Tuesday/Aspirin.pdf… [read more]


Nebulas, Massive Clouds Essay

… Large stars can burn out faster than small stars because they burn energy at a higher rate. This is why many small stars will have a longer life span than a larger star: they do not consume their fuel as fast and thus remain alive longer. When the star stars to burn up its helium reserves, the star is on its last years of its life. This is because it requires more energy to fuse helium than it does hydrogen, thus expending the star's energy rapidly. When the star starts burning helium, its temperature and intensity can be stronger than ever before during its life cycle. This stage of the star's life is referred to as the red giant stage. Red giants are bright but are becoming less stable than they were before. Their volatility is due to their burning of carbon. The death of stars is difficult to document and measure.

A Hertzsprung-Russel (HR) Diagram represents stars visually as dots, plotted on a graph using two axes: absolute magnitude (which is basically luminosity, measured in energy emissions per second), and surface temperature measured in Kelvin. What the HR Diagram is especially good for is showing the relational values of the stars' luminosity and temperature. The reference point for the HR diagram is the sun, which provides a means by which to visualize the magnitude or temperature of other stars in relation to it. Basically, stars are ranked according to relative hotness and brightness. Most stars fall within a median range called main sequence, which is akin to the average of stars. Tjhis is because most stars follow a predictable pattern in that large stars can burn bright and hot. Some, but not all, HR Diagrams, also include factors like the color of a star, measured with spectrophotometers.

Reference

"Star Life Cycle." Retrieved online: http://sunshine.chpc.utah.edu/Labs/StarLife/starlife_main.html… [read more]


Properties of a Carbon Atom Term Paper

… -Describe the basic characteristics of cancer cells?

Cancer cells can be deadly and harmful to all the living things they come into contact with. Cancer cells lose the ability to communicate with other cells through chemical signals. They also lose sensitivity to anti-growth signals from surrounding cells. These signals normally restrict cellular growth. Cancer cells do not have a fixed lifespan. As long as they are able get the nutrients needed to survive, cancer cells are essentially immortal. They will continue to live and divide at an uncontrolled pace unless something happens to stop them. Malignant cells that cause cancer all have the ability to evade the body's cancer surveillance system as well.

-Evaluate why meiosis and sexual reproduction are important in responding to the changing environment?

In meiosis, variation occurs, because each gamete (either sperm or egg) contains a mixture of genes from two different parent chromosomes in sexual reproduction. In other words, the genetic coupling of non-identical DNA takes place in meiosis. It results in an offspring, which has the genetic material of two different individuals. A new combination of genetic information is produced in the gametes. Therefore, in meiosis, the characteristics of parent chromosomes are combined with the characteristics of offspring chromosomes, which ultimately results in a new and unique set of chromosomes. These chromosomes contain the basic DNA chain, which determines the physical and genetic characteristics of the child.

-List the three domains of life and summarize two characteristics that define each of the three domains.

The three domains of life are the Archaea Domain, the Bacteria Domain and the Eukarya Domain. The Archae Domain consist of prokaryotic cells which are membranes. They can withstand high temperatures. Bacteria are prokaryotic cells too but they are made of fatty acid chains. This domain is very diverse and their trillions of species. The Eukarya Domain are eukaryotic cells. Animals, plants and fungi are all part of this domain.

-Discriminate between ancestral and derived traits?

A derived trait is a trait that the current organism has, but the previous one did not have.

An ancestral trait is a trait that you, and…… [read more]


Corrosion in Reinforced Concrete Structures Research Paper

… Corrosion in Reinforced Concrete Structures

The report demonstrates the corrosion process in reinforced concrete structures. Corrosion is a gradual destruction of concrete, metal and steel structure generally caused by the chemical reactions. The chemical process of corrosion involves the combination… [read more]


Chadwick Learned to Love Research Paper

… It only took Chadwick one month to discover the conclusive evidence that the neutron did indeed exist; the journal Nature published the report in 1932.

B. Chadwick described a neutron as " a highly penetrating neutral particle with a mass similar to the proton," ("The Neutron: Chadwick 1932," n.d.)

C. Chadwick explained the phenomenon in terms of snooker balls, noting that when the alpha particles from a radioactive source hit a nuclei, a proton is knocked free leaving behind a particle -- suggesting that the neutron is the same mass -- just as when a snooker ball is hit by a ball of the same mass it remains stationary.

IV. The Aftermath

A. Chadwick earned the Nobel Prize for his work.

B. Unfortunately, the work from Chadwick's discovery would be harnessed for great evil, causing Chadwick considerable consternation

1. He disparaged the way science was headed toward harnessing discoveries like his for military purposes.

2. He especially feared the American control of science (Oliphant, 1982).

C. Chadwick's discovery led to a "revolution in warfare," a "new source of energy," and "fundamental changes" to the study of science (Oliphant, 1982).

Reference

"1932 Discovery of Neutrons by James Chadwick." Retrieved online: http://library.thinkquest.org/27954/neutron.html

Breithaupt, J. (2000). New Understanding Physics for Advanced Level Fourth Edition. Nelson Thornes.

Colwell, C.H. (2012). Famous experiments: the discovery of the neutron. Retrieved online: http://dev.physicslab.org/Document.aspx?doctype=3&filename=AtomicNuclear_ChadwickNeutron.xml

Nave, R. (n.d.). Discovery of the neutron. Retrieved online: http://hyperphysics.phy-astr.gsu.edu/hbase/particles/neutrondis.html

Oliphant, M. (1982). The beginning: Chadwick and the neutron. In Bulletin of the Atomic Scientists.

"The Neutron: Chadwick, 1932," (n.d.). Retrieved online: http://www-outreach.phy.cam.ac.uk/camphy/neutron/neutron5_1.htm… [read more]


Heat and Temperature Essay

… Heat and Temperature

The Kinetic Theory of Matters is mainly focused on the facts that everything is composed out of moving particles and this movement is accelerated if temperature is increased. Heat is transferred through atoms or molecules moving and thus transmitting energy. A body's temperature can be found by measuring the average kinetic energy of the particles that it contains.

Heat can be transferred through three processes: conduction, convection, and radiation. Conduction is the process during which heat is transferred through a solid body that is heated. During the process of convection, particles that are heated transmit heat to another body. Radiation is different from conduction and convection because it can transmit heat through open space, given that it does not require contact between two matters in order to do so.

The Universe is composed out of two elements: matter and energy. Considering that matter is composed out of atoms and molecules, these two are influenced in constantly moving because of energy. Energy causes atoms and molecules to collide with each-other or to simply move back and forth, vibrating. By moving, atoms and molecules generate a type of energy referred to as either heat or thermal energy. Heat is present in all matter, regardless of the temperature matter has. Energy can easily change form and it can be converted into a series of forms. Heat energy can result from a multitude of energy forms, ranging from mechanical energy until nuclear energy. Heat energy occurs when a body transfers its warmth to another body, when each of the bodies had a different temperature.

In order to determine temperature, one must examine the average heat of the molecules and atoms contained by a body. Atoms and molecules are not always travelling at the same speed, thus meaning that some can move slower and others can move faster. The number of atoms and molecules in a substance cannot influence the respective substance's temperature, since the measurement is average. Even when a particular object has a large number of particles in addition to another, the temperature of the two bodies can be the same.

Temperature is something people feel on a daily basis, considering that weather can largely influence the temperature in our bodies. Individuals most often relate to temperature when they consider the terms hot and cold. Temperature is determined by thermometers that can be graded in a variety of ways, with some of the most often scales used at determining temperature being Celsius (used by most of the world), Fahrenheit (used rarer, by…… [read more]


Electrolytic and Voltaic Cells Research Paper

… Electrolytic and Voltaic Cells

An electrolytic cell is a cell that is made up of two electrodes touching an electrolyte and that causes a chemical reaction when connected to an external source of electricity. The electric energy is used to decompose chemical compounds and the process is referred to as electrolysis, this leads to an increase in the chemical energy. This cell has three major components, the electrolyte, an anode, and a cathode. The anode and cathode are usually referred to as electrodes. The electrolyte is normally water solution or any other solvent that ions can dissolve in example being salts like sodium chloride. The application of external voltage to the electrodes makes the electrolyte to produce ions which flow to and from the electrodes where redox reaction takes place. The applied electrical energy reverses the effect of impulsive chemical reactions.

A voltaic cell is a device that converts chemical energy into electric energy this it does by deriving electrical energy from the chemical reactions that take place within, it is also referred to as an electrochemical cell. This device is made up of two distinct metals linked by a salt bridge or single half-cells separated using a porous film. Every half-cell consists of a metal and a salt solution corresponding to the metal. In the salt solution is contained the metal's cation and an anion to bring balance on the cation's charge. Basically the half-cell has the metal in two oxidation states and the type of reaction that takes place within it is redox reaction. In this cell, one metal is capable of reducing the cation of the other; on the other hand, the first metal can be oxidized by the cation. There is need to avoid the mixing of the two half-cells thus they must be physically separated. The quantity of electrons transferred in either direction must be equal thus combining the two half-cells gives the whole-cell electrochemical reaction. Therefore, to get the voltage of the cell, the voltages of the two half-cells are added.

Therefore, the contrast that…… [read more]


Genetics and Evolution Essay

… Biology

Genetics and Evolution

UCLA chemists report having created a synthetic "gene" that could capture heat-trapping carbon dioxide emissions, which contribute to global warming, rising sea levels and the increased acidity of oceans. They have taken both organic and inorganic units and joined them into a synthetic crystal which codes information like DNA does. It is in no way as sophisticated as DNA, but it is new to the fields of chemistry and materials science (Chemists Create Synthetic 'Gene-Like' Crystals for Carbon Dioxide Capture, 2010).

In the early 1990s, classes of materials called metal-organic frameworks (MOF's) were invented. These are sometimes described as crystal sponges because the workings can nearly be changed at will. MOF's have pores or openings in which gases can be stored that are usually difficult to store and transport. Molecules can go in and out of the pores unhindered. UCLA chemists have created crystals of metal-organic frameworks in which the sequence of multiple functionalities of varying kinds and ratios act as a synthetic gene. With…… [read more]


Nitrogen Cycle Thesis

… ¶ … Nitrogen Cycle

As an essential element in the formation of amino acids and thus proteins -- the basic constituents of all organic matter -- nitrogen is a necessary nutrient to absolutely all life forms on Earth (Killpack & Bulchholz 2010). This is no less true of human beings than it is of other organisms; almost every system in the human body has at least an indirect reliance on proper nitrogen levels being maintained. All life is built of proteins, but nitrogen is even more important in terms of metabolism, growth, and reproduction (Pidwirny 2006). In addition to being one of the basic elemental constituents of amino acids and proteins, nitrogen is also necessary in nucleic acids -- like DNA -- meaning that cellular reproduction and repair cannot occur without adequate nitrogen supplies. It is for this reason that every system in human beings -- and indeed in all animals -- is dependent on nitrogen.

It would seem, then, that nitrogen must be readily available to all of these organisms, but this is not actually the case. Though nitrogen is the most abundant element in the Earth's atmosphere, nitrogen gas -- N2 -- cannot be utilized by most life forms. This is where the nitrogen cycle comes into play. Through a complex series of chemical changes wrought by various organisms and certain other processes, the nitrogen gas in the atmosphere is converted into more usable forms and, after being used as a nutrient by organisms throughout the web of life is eventually returned to the environment and the atmosphere (Elmhurst 2009). There are many different chemical changes that occur at each step in the nitrogen cycle, each of which has major important effects on both the ability for organisms to utilize nitrogen and on the environment as a whole.

It is possible for nitrogen in the atmosphere to…… [read more]


Nitrogen Cycle Thesis

… ¶ … Nitrogen Cycle

As the most abundant element in the Earth's atmosphere, nitrogen might be thought to be an easily accessible nutrient for the planet's many life forms. In fact, however, nitrogen's abundance has very little to do with its availability as a nutrient in any sort of direct way. Before the nitrogen gas -- N2 -- in the atmosphere can be utilized by plants -- and before those plants can be eaten by organisms higher on the food chain like human beings -- it has to be converted into different forms (Kimball 2008). Namely, it has to be taken out of its gaseous state and converted to other forms in other molecules in order to be absorbed and used by plants (Harrison 2003). The process by which this occurs is one of the most remarkable and one of the most necessary cycles to have come into existence, and is both fairly simple and, on a deeper and more practical level, stil not fully understood.

The first step in the nitrogen cycle is nitrogen fixation. In this process, bacteria and some other microorganisms in the Earth's soil convert atmospheric nitrogen gas into ammonia, managing to split each double-atom molecule of nitrogen gas and pairing each individual atom with three hydrogen atoms (Harrison 2003). The manner in which bacteria manage this feat -- both the splitting of the nitrogen gas molecule and the fusion of the ammonia molecule -- is not fully understood by science; industrialization has allowed for the human creation of ammonia from the raw elements, but it requires great heat and pressure -- far more energy than the bacteria and microorganisms exert doing the same job (Kimball 2008). Regardless, this process does take place, and the ammonia is either used directly by plants or is further converted by bacteria before being taken up by other organisms.

At this point, the nitrogen has become fixed and is now…… [read more]


Teaching a Textbook Passage Thesis

… Teaching a Textbook Passage

Most of the Universe consists of matter and energy. Energy is the capacity to do work. Matter has mass and occupies space. All matter is composed of basic elements that cannot be broken down to substances with different chemical or physical properties. Elements are substances consisting of one type of atom, for example Carbon atoms make up diamond, and also graphite. Pure (24K) gold is composed of only one type of atom, gold atoms. Atoms are the smallest particle into which an element can be divided. The ancient Greek philosophers developed the concept of the atom, although they considered it the fundamental particle that could not be broken down. Since the work of Enrico Fermi and his colleagues, we now know that the atom is divisible, often releasing tremendous energies as in nuclear explosions or (in a controlled fashion in) thermonuclear power plants."

On-Line Biology Book

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

Before opening the textbook to this rather dense passage, I would begin a discussion to ascertain what the students knew and understood of their world, and specifically the topics discussed here. I expect many students would have heard of atoms, and might have a basic understanding of what atoms are. Tapping into their ideas will allow this passage to be tied into what they already know, aiding their understanding of these complex though relatively basic…… [read more]


Origin of Life Essay

… ¶ … Origin of Life

There are currently many different competing theories on how life originated on this planet. One of these theories involves the early state of the atmosphere. According to this theory, the first step in the origins of life was the spontaneous formation of carbon compounds in Earth's then carbon-rich atmosphere. There is substantial evidence that these compounds could have formed -- they are a common occurrence throughout space, and experiments have shown that even amino acids, the building blocks of proteins, can be formed under conditions similar to those that existed at a certain point in the Earth's past. The theory goes that after these amino acids and other organic compounds formed, they eventually came together to form more complex systems, at some point coalescing into unicellular organisms. There is no way to prove, however, that this is actually what happened, and as yet no mechanism described for how the various simple organic compounds could have organized themselves into more complex cells that exhibited signs of life. The process would have taken millennia at the least, and time is one of the few things that cannot be…… [read more]


Collision Model: Explanation and Application Research Paper

… At the time of collision, bonds are stretched and broken as new bonds are made. Breaking these bonds and rearranging the atoms during the collision requires the input of energy" (Hutchinson 2006).

Different experimental parameters will thus impact the product… [read more]


Silica Use Term Paper

… Silica Use

Silica usage and safety

Silica is the second most commonly found mineral on earth and comprises almost thirty percent of the Earth's crust by weight. (Silica Dust Exposure) Silcia, or silicon dioxide (SiO2) also known as alpha silica… [read more]


Due to His Work Term Paper

… For example:

If there was a gas that exerted 10 atm of pressure and took up a space of 3 liters, and it was decided to expand the space to 7 liters, what would be the new pressure, assuming that… [read more]


Radiometric Dating in 1896 Term Paper

… The rate of decay is expressed in terms of an isotope's half-life, or rather the time for one-half of a particular radioactive isotope in a sample to decay (Time pp). Although most radioactive isotopes lose their radioactivity within a few days or years, some, however, are slow to age, and several of these are used as geologic clocks (Time pp). Dating rocks by these radioactive clocks is rather simple in theory, however, the laboratory procedures are complex (Time pp). The numbers of parent and daughter isotopes within each specimen are determined by a variety of analytical methods, and the difficulty lies in the precision of measuring very small amounts of isotopes (Time pp).

All carbon in living organisms has a constant proportion of radiocarbon to non-radioactive carbon, and after the organism's death, the amount of radiocarbon gradually decreases as it reverts to nitrogen-14 by radioactive decay, and by measuring the amount remaining, the amount of carbon-14 in the materials can be calculated and the time of death can be determined (Time pp).

This radiocarbon timepiece has become a very useful and efficient tool in dating important episodes in the recent prehistory and history of man, however, due to the relatively short half-life of carbon-14, this method of calculation is limited to dating events that have taken place only within the past 50,000 years (Time pp).

Works Cited

Radiometric Dating

http://www.gpc.edu/~pgore/geology/geo102/radio.htm

Radiometric Time Scale

http://pubs.usgs.gov/gip/geotime/radiometric.html… [read more]


Radioactivity the Transformation of Atoms Term Paper

… Contrary to this the gamma radioactivity is associated with transmutation of the nucleus. It is the consequence of emission by the nucleus, of an electromagnetic radiation such as visible light or X-rays, however, are considered more energetic. (What is radioactivity?)

The energy generated by the process of radioactivity has significant military and industrial utilities. But the rays emitted out of radioactive substances results in radiations sickness and such substances are required to be dealt with much care. The nuclei of elements in the process of radioactivity tend to be highly unstable and are taken to be undergoing persistent disintegration known to be radioactive decay. (Radioactivity: The Columbia Encyclopedia) Radioactive decay is considered to be a group of various processes by which emission of subatomic particles is evident by the unstable atomic nuclei. Radioactive decay is applied in the tools of radio isotopic labeling which is considered useful in tracking the path of a chemical substance through a complex system like inside the living organism. (Radioactive decay: Wikipedia, the free encyclopedia)

References

Radioactive decay. Wikipedia, the free encyclopedia. Retrieved from http://en.wikipedia.org/wiki/Radioactivity Accessed on 17 February, 2005

Radioactivity in nature. Idaho State University. Retrieved from http://www.physics.isu.edu/radinf/natural.htm

Accessed on 17 February, 2005

Radioactivity. The Columbia Encyclopedia. 2001. Retrieved from http://www.bartleby.com/65/ra/radioact.html Accessed on 17 February, 2005

What is radioactivity? Retrieved from http://www.ccr.jussieu.fr/radioactivite/english/what_is_radioactivity.htm Accessed on 17 February, 2005… [read more]


Beginnings of Life on Early Earth Term Paper

… ¶ … Life on Early Earth

Questions related to the origins of life on Earth have always been a cause for scientific investigation and suppositions. If we refer to the naturalistic approach, than the evolutionary process is a justified explanation… [read more]


Polymer Analysis (Kevlar) Brief History Term Paper

… 6). The two compounds, Kevlar and Nomex, are distinguished by the structure of their polymer chains, with Kevlar containing para-oriented phenyl rings and Nomex containing meta-oriented rings as shown in Figure 1 below:

Figure 1. Nomex and Kevlar Polymer Chains… [read more]

12. . .
NOTE:  We can write a brand new paper on your exact topic!  More info.