Guns, Germs, and Steel essays

Guns, Germs, and Steel essays Guns, Germs, Steel, and controversy: Diamonds unique look at evolution and history. Through out Guns, Germs, and Steel, Jared Diamond attempts to explain the dominance of certain ethnicities. The backbone to this book and the questions that Diamond asks and answers, stem from a question asked of him in 1972 by a local politician in New Guinea named Yali. Our conversation began with a subject then on every New Guineans mind the rapid pace of political developments. What Yali wanted to know was why New Guinea and other cultures around the world seemed behind in technology. Why were the Europeans the dominant force in the world? Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people had little cargo of our own? As Diamond puts it, Yalis question can be stretched out to not just the whites and New Guineans, but most of the world and whites. Why did wealth and power become distributed as they now are, rather than in some other way? For instance, why werent native Americans, Africans, and Aboriginal Australian s the ones who decimated, subjugated, or exterminated Europeans and Asians? In the next 400 pages, Diamond does everything to convince the reader of all the agricultural and environmental reasons for this, while trying to bury the old theory of intellectual racism. That is, the belief that Europeans and Asians have a naturally higher intellect. After reading I found that his theory of environment and agriculture had a very strong base to it and made a lot of sense. He makes his points clear and very factual, using examples throughout history and his own personal life in some instances to hammer his point home. However Im a little skeptic of him disregarding at all the possibility of a certain race being inherently smarter than another. Although he makes a few points towards his theory, he dodges it for the...

Electron Domain Definition and VSEPR Theory

Electron Domain Definition and VSEPR Theory In chemistry, the electron domain refers to the number of lone pairs or bond locations around a particular atom in a molecule. Electron domains may also be called electron groups.  Bond location is independent of whether the bond is a single, double, or triple bond. Key Takeaways: Electron Domain An atoms electron domain is the number of lone pairs or chemical bond locations that surround it. It represents the number of locations expected to contain electrons.By knowing the electron domain of each atom in a molecule, you can predict its geometry. This is because electrons distribute around an atom to minimize repulsion with one another.Electron repulsion is not the only factor that affects molecular geometry. Electrons are attracted to positively charged nuclei. The nuclei, in turn, repel each other. Valence Shell Electron Pair Repulsion Theory Imagine tying two balloons together at the ends. The balloons automatically repel one another. Add a third balloon, and the same thing happens so that the tied ends form an equilateral triangle. Add a fourth balloon, and the tied ends reorient themselves into a tetrahedral shape. The same phenomenon occurs with electrons. Electrons repel one another, so when they are placed near one another, they automatically organize themselves into a shape that minimizes repulsions among them. This phenomenon is described as VSEPR, or Valence Shell Electron Pair Repulsion. Electron domain is used in VSEPR theory to determine the molecular geometry of a molecule. The convention is to indicate the number of bonding electron pairs by the capital letter X, the number of lone electron pairs by the capital letter E, and the capital letter A for the central atom of the molecule (AXnEm). When predicting molecular geometry, keep in mind the electrons generally try to maximize distance from each other but they are influenced by other forces, such as the proximity and size of a positively-charged nucleus. For example, CO2 has two electron domains around the central carbon atom. Each double bond counts as one electron domain. Relating Electron Domains to Molecular Shape The number of electron domains indicates the number of places you can expect to find electrons around a central atom. This, in turn, relates to the expected geometry of a molecule. When the electron domain arrangement is used to describe around the central atom of a molecule, it may be called the molecules electron domain geometry. The arrangement of atoms in space is the molecular geometry. Examples of molecules, their electron domain geometry, and molecular geometry include: AX2 - The two-electron domain structure produces a linear molecule with electron groups 180 degrees apart. An example of a molecule with this geometry is CH2CCH2, which has two H2C-C bonds forming a 180-degree angle. Carbon dioxide (CO2) is another linear molecule, consisting of two O-C bonds that are 180 degrees apart.AX2E and AX2E2 - If there are two electron domains and one or two  lone electron pair, the molecule can have a bent geometry. Lone electron pairs make a major contribution to the shape of a molecule. If there is one lone pair, the result is a trigonal planar shape, while two lone pairs produce a tetrahedral shape.AX3 - The three electron domain system describes a trigonal planar geometry of a molecule where four atoms are arranged to form triangles with respect to each other. The angles add up to 360 degrees. An example of a molecule with this configuration is boron trifluoride (BF3), which has three F-B bonds, each forming 120-degree angles. Using Electron Domains to Find Molecular Geometry To predict the molecular geometry using the VSEPR model: Sketch the Lewis structure of the ion or molecule.Arrange the electron domains around the central atom to minimize repulsion.Count the total number of electron domains.Use the angular arrangement of the chemical bonds between the atoms to determine the molecular geometry. Keep in mind, multiple bonds (i.e., double bonds, triple bonds) count as one electron domain. In other words, a double bond is one domain, not two. Sources Jolly, William L. Modern Inorganic Chemistry. McGraw-Hill College, June 1, 1984. Petrucci, Ralph H. General Chemistry: Principles and Modern Applications.  F. Geoffrey Herring, Jeffry D. Madura, et al., 11th Edition, Pearson, February 29, 2016.