16Nov 2014 by Vincent Summers 1 Comment

Organic Chemistry: What is Ring Strain?

Chemistry
[caption id="attachment_16313" align="alignright" width="440"] Cyclopropane suffers from ring strain.[/caption] Carbon ring strain? What is that? Let's begin at the beginning. The element carbon is one of a small number of elements that can bond to itself repeatedly. Compare gases such as oxygen (O2), called diatomic gases because generally only two atoms unite. Oxygen is exceptional in that it does form the triatomic molecule, ozone (O3). However, carbon can form even lengthy chains. Thus, carbon can form, not only methane (CH4), but ethane (H3C-CH3), propane (H3C-CH2-CH3), butane (H3C-CH2-CH2-CH3), pentane (H3C-CH2-CH2-CH2-CH3), and so on. Curiously, carbon can also close those chains to form rings, much as a woman can close a string of pearls about her neck using a clasp. [sc name="MidArticleAdsense"] Cyclization Although methane cannot so close, nor can ethane, the…
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16Nov 2014 by Vincent Summers No Comments

Organic Chemistry: What is a Lactam?

Chemistry
Most have never heard of a lactam. What is it? How can it be produced? Compounds are chemicals formed by combining two or more different atoms, the basic building blocks of matter. Organic compounds contain carbon, frequently bonded to itself, whether in chains, rings, or some other geometric structure. There are so many organic compounds, they must be categorized according to "functional groups." Functional groups are specialized structures within a compound that may contain a special atom, such as nitrogen, sulfur, phosphorous, etc. One kind of compound categorized by functional group is an amide. An amide results when an organic acid group reacts with a nitrogen-containing amine group and loses water. A lactam is a special kind of amide. It may serve as an intermediate in forming heterocyclic rings. Inorganic…
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16Nov 2014 by Vincent Summers No Comments

Terpenes and Terpenoids: Isoprene Rule

Chemistry
There are thousands of chemical compounds in nature. They are divvied up into categories or classifications. These include hormones, alkaloids, vitamins, neurotransmitters, enzymes, proteins, and nucleic acids. One group of chemicals follows a structure rule called the isoprene rule. Many every day substances are part of this group. One example is turpentine. Another is beta-carotene (the source of the orange color in carrots). Chemicals such as these derived from isoprene are called terpenoids. Structure and Statement of the Isoprene Rule Isoprene consists of carbon and hydrogen. But it is not limited to single bonds. See the image of isoprene (C5H8) featured with this article. The double lines stand for double bonds. Since the carbon pairs involved have two bonds rather than one, a hydrogen atom is missing from each of them.…
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15Nov 2014 by Vincent Summers No Comments

Analytic Geometry: The Parabola

Mathematics
What is a parabola, and of what use is it? If a sheet of paper is likened to an infinite plane in space, the x- and y-axes, drawn at right angles to each other, provide a means of describing each point on the plane of the paper in terms of an x and a y value. Thus the point (1, 3) tells us that beginning at the origin or center where the x-axis crosses the y-axis, if we travel one unit to the right and then three units up, we will have reached the point we seek. Introducing the Parabola Now we will pass on to describing a parabola.1 The parabola is an important mathematical "curve," inasmuch as it describes, mathematically, the behavior of a number of important actions, such…
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15Nov 2014 by Vincent Summers No Comments

Analytic Geometry: The Hyperbola

Mathematics
[caption id="attachment_6399" align="alignright" width="380"] Simple hyperbola with asymptotes. Image by author.[/caption] The parabola, ellipse, circle, and hyperbola are all termed conic sections. This means that a plane that cuts into a cone in just the right way will generate one of these figures. We will consider the basic equation of a hyperbola and graph one. Equation of an Hyperbola It may be recalled the equation for an ellipse centered at the origin is, x2/a2 + y2/b2 = 1 where 2a is the length of the ellipse and 2b is its height. The equation for an hyperbola centered at the origin is very similar, x2/a2 - y2/b2 = 1 The graph of this function is completely different from that of an ellipse. Let's look at a very basic one, for which…
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14Nov 2014 by Vincent Summers No Comments

Introduction to Cylindrical Coordinates

Mathematics
What are cylindrical coordinates? A coordinate system is a system that provides a way to describe points and other features of geometric figures in Euclidean space. Generally the best coordinate system is that system which adequately does the job in simplest fashion. In this article, we will use (r, Φ, z) for our new coordinate system. Many use this, but others use a different assortment of letters, unfortunately. Forewarned is forearmed. Cylindrical Coordinates - Introspection When we're working in two dimension, we are able to draw our coordinate axes using the sheet of the paper, representing a plane. Two orthogonal axes are drawn, one horizontal the other vertical. When using r and Φ the way we view the axes is really different from how we view them when they represent x…
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14Nov 2014 by Vincent Summers 3 Comments

Hydrogen Metal?

Chemistry
We're familiar with hydrogen as a gas, but hydrogen metal? Could it be that's what hydrogen is? [Artist's conception at right.] There are more than 100 substances listed in the Periodic Table of the Elements. This table is called "periodic" because, although each column is completely different, the properties of one row are very similar to the properties of the next. If you start on the left with an alkali metal, and you go through a row, you go to the next row and another alkali metal. An Anomaly Most of the alkali metals, such as lithium, sodium, and potassium, are very similar. They are soft, reactive, silvery solids. They have one outer electron and conduct electricity. They are easily cut with a knife. But, there is an exception –…
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14Nov 2014 by Vincent Summers 3 Comments

Why Electroless Plating and Electroplating?

Chemistry
[caption id="attachment_6370" align="alignright" width="440"] Nickel Plating[/caption] Many items need require a coating of metal. Such can be applied in a couple of ways. One way is electroless plating. Another way is electroplating. Chrome handles on car doors are plastic with a veneer of metal. When you look in a mirror, you see your reflection in a sheet of glass with a metal film on the back. If you wear gold eyeglasses, there is a super thin coat of gold over base metal. Most plating uses a water solution containing metal salts. If an electric source is used to deposit the plate, the process is electroplating. If no electric source is used, it is auto-catalytic or electroless plating. How do these work? We will discuss the basics, beginning with electroplating. Electroplating…
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13Nov 2014 by Vincent Summers No Comments

Hydrogen Bonding Effects at Various Levels

Chemistry
[caption id="attachment_6362" align="alignright" width="440"] Hydrogen Bonding - a DNA step.[/caption] Hydrogen bonding ranges from simple interactions to protein folding and the double helix of DNA. Atoms bond to each other in a variety of ways. Among these are ionic bonds. Ionic bonds feature electron transfer between atoms. Then there are covalent bonds. These share electrons between atoms. There are also and metallic bonds. These consist of a matrix of atoms interlaced with mobile valence electrons. In addition to these major forms of bonding, there are weaker yet highly important bond types. Foremost of these are hydrogen bonds. Description A hydrogen bond is a tenuous electrostatic attraction between an already bonded atom of hydrogen and a second (electronegative) atom. These two atoms can be located in the same molecule or different…
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12Nov 2014 by Vincent Summers 1 Comment

Inert Gas Compounds?

Chemistry
[caption id="attachment_16914" align="alignright" width="440"] Xenon Tetrafluoride[/caption] There are millions of compounds. Some of them are even inert gas compounds. We were taught in high school that there are special, inert gases in the Periodic Table. These include radon and krypton, and are found in the column furthest to the right of the table. But that was then. Now we will learn that not all of those gases are all that inert. In addition to being called inert, the far right column gases are sometimes called rare or noble gases. These gases have a completed outer shell of electrons. So it would seem they should have no tendency to gain or lose electrons. But just how true is that? Can inert gases form compounds? Platinum Hexafluoride Platinum hexafluoride is formed by…
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