## Electronegativity of Atoms: What are Determining Factors

[caption id="attachment_24637" align="alignright" width="480"] 5d molecular orbital - Image Dhatfield[/caption] When two different types of atom are bonded together, they do not share their bond electrons equally. This is because each type of atom possesses its own charge environment, which results in an atom’s electronegativity. Electronegativity is the measure of an atom’s ability to attract additional electron density to itself. For example, Sodium seeks to give an electron to become a positive ion, Na+. It has a very low electronegativity. Iodine wants to gain an electron to become a negative ion, I-. It has a relatively high electronegativity. Charge Environment Atoms vary in electronegativity, and bonds vary according to constituent atom electronegativities. The electronegativity of an atom depends upon its charge environment. That environment depends primarily on three things... Distance…

## Simple Algebra II Graph Symmetries Discussion and Examples

[caption id="attachment_17854" align="alignright" width="480"] Typical functions in two variables.[/caption] College preparatory classes in high school often include Algebra and Algebra II. Perhaps the most memorable aspect of Algebra II is the two-dimensional (2D) graphing of mathematical functions in two variables. This is typically introduced beginning with the Cartesian coordinate system. The generic function is written y = f (x). This reads y equals a function of x. See the illustration for some examples of functions. Cartesian Coordinate System In the Cartesian system, two variables, often x and y, are assigned their own line, one horizontal (x), one vertical (y). The intersection between the two axes is called the origin, and is assigned the value (0, 0). The value of x is the value written on the left in the brackets;…

## XY-Coordinate System Symmetry with Examples

[caption id="attachment_28582" align="alignright" width="480"] Image Department of Energy[/caption]In high school mathematics, the topic of symmetry is bound to arise. Especially is this so in analytic geometry. For curve C, what is its XY coordinate system symmetry? How is it symmetric about the y-axis? The x-axis? The origin? The line y = x? The line y = -x? Symmetric about some point other than the origin? Symmetry About the Y-Axis Symmetry about the y-axis means that if there is a curve that lies to the right of the y-axis, there is an identical copy of it to the left of the y-axis. That is, it is symmetrical if each x value can be replaced with –x. Thus, the parabola y = 1/2x2 is symmetric with regard to the y-axis. For every…

## Drawing Single Bond Organic Hydrocarbons

[caption id="attachment_5904" align="alignright" width="440"] Straight Chain Pentane[/caption] Carbon is one of the few elements that readily bonds to itself, thus allowing the formation of macromolecular structures. It is not at all an uncommon thing to see a lengthy carbon-based structure, possessing molecular weight well up into the tens of thousands. Compare this with an “ordinary” molecule such as table salt, sodium chloride (NaCl) with its molecular weight—a mere 58. Drawing Single Bonded Organic Structures Ordinarily, carbon compounds are written by chemists in as simple a form as possible. Thus, drawing single bond organic hydrocarbons such as n-hexane, we write, C₆H₁₄ or, a little more in detail, CH₃(CH₂)₄CH₃ or, perhaps even, CH₃‒CH₂‒CH₂‒CH₂‒CH₂‒CH₃ [sc name="MidArticleAdsense"] Need Greater Specificity? The problem is, carbon single bonds possess tetrahedral symmetry. This means that single bonds…