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Tuesday, January 2

  1. page orbital notations edited ... Second, because of their magnetic fields, electrons will not pair up with the same spin in an …
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    Second, because of their magnetic fields, electrons will not pair up with the same spin in an orbital. This means that every single electron in an atom will have a unique electron configuration, which is the basis of the Pauli Exclusion Principle.
    {pauli-exclusion-principle.JPG} Source: chemistry.tutorvista.comUsing orbital notation, you can now identify the energy level, sublevel, orbital, and spin state of any electron in any atom on the periodic table.
    Here is a flash animation for the order of filling for the first 5 energy levels.
    Here is an online tool for visualizing orbital notations.

    (view changes)
    5:18 pm
  2. page orbital notations edited ... {orbital-boxes.jpg} And the arrangement of these orbitals follows that of electron configura…
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    {orbital-boxes.jpg}
    And the arrangement of these orbitals follows that of electron configuration notations.
    This online tool will depict orbital notation and electron configuration for you.
    Now for some rules.
    First, electrons are all negatively charged. As they occupy a sublevel with multiple orbitals, they will not pair up unless they have to. This repulsion is the reason behind Hund's Rule, which essentially says to fill orbitals with electrons individually first.
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    5:16 pm

Wednesday, October 4

  1. page measurements edited ... {buret1.jpeg} Answers: A. 2.0 x 10^2 mL, or 200 (middle zero mL +/- 3 mL (each calibrat…
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    {buret1.jpeg}
    Answers:
    A. 2.0 x 10^2 mL, or 200 (middle zeromL +/- 3 mL (each calibration mark is significant; last one is not)25 mL, so 25 x 0.1 = 2.5, rounded up to 3.)
    B. 190185 mL +/- 3 mL (same as above)
    C. 125 mL
    D. 5.0 x 10^2
    +/- 3 mL or
    D.
    500 mL (only middle zero is sig.)+/- 10 mL
    E. 293294 mL +/- 0.5 mL
    F. 18.0 mL +/- 0.1 mL
    G. 1.42 mL +/- 0.01 mL
    H. 21.15 mL +/- 0.01 mL
    I. 0.10 mL +/- 0.01 mL
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    5:10 am
  2. page accuracy and precision edited When taking a measurement, there will always be some amount of error. The degree of error depends o…
    When taking a measurement, there will always be some amount of error. The degree of error depends on the device being used to take a measurement and is referred to as its uncertainty.
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    one might be lead to think. These
    When a measurement is taken, the device used to carry out the measurement will dictate the accuracy of that measurement. If you were to measure the thickness of a coin, using a digital caliper accurate to the tenth of a millimeter would be much better than using a meter stick.
    In general, the more increments (lines between lines) on a measuring device the more accurate it is. A 100.0 mL graduated cylinder has lines representing each milliliter, whereas a 100 mL beaker only has lines estimating every 10 milliliters.
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    4:16 am

Tuesday, September 12

  1. page home edited ... Download a printable periodic table with ion tables: {periodic-table14.pdf} {per-table-sm.jp…
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    Download a printable periodic table with ion tables: {periodic-table14.pdf}
    {per-table-sm.jpeg} Click Here!
    ...
    {Laboratory Report Template.doc}Template 1.1.doc}
    {lab rep.jpeg} Click Here!
    Download SI Units and Conversion Factors: {SI Units, Properties.doc}
    (view changes)
    6:03 am

Monday, September 11

  1. page Alchemy edited ... So, Greece was not alone in its advanced schools of thought concerning chemistry. Alchemy .…
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    So, Greece was not alone in its advanced schools of thought concerning chemistry.
    Alchemy
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    as the Greeks, Persians, Chinese,
    {alchemical symbosl.jpg}
    Key terms:
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    7:02 am
  2. page Alchemy edited ... These elements interact with one another and even depend on one another (for example, wood, ma…
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    These elements interact with one another and even depend on one another (for example, wood, made from earth, will burn - create fire - but it requires air, and produces water in the process).
    All materials originate from one of the four basic elements.
    ...
    Elements {aristotle.jpg} Aristotle
    The element mercury (Hg) was identified, and its extraction from cinnabar (its ore) was described, although this description was likely taken from older manusctipts from Egypt or Spain.
    The science of medicine also saw some advancements in this era, thanks to Hippocrates. He is what the modern "Hippocratic Oath" is named after. He also acted as an early pharmacist, prescribing willow bark as a painkiller.
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    6:59 am
  3. page Alchemy edited ... The science of chemistry saw major advances in the era of the Ancient Greeks. Two theories aro…
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    The science of chemistry saw major advances in the era of the Ancient Greeks. Two theories arose which attempted to describe the physical and chemical properties of substances.
    {democritus.jpeg} Democritus
    Plato (400 B.C.) described pure metals as "elemental" (stoicheia), the Greek word from which the term stoichiometry is derived.
    A Greek philosopher, Democritus (ca 400 B.C.), posed one of the first theories on the elements. He was interested in the components, if any, of metals such as gold. After much investigation, he proposed that gold was "uncuttable", meaning gold contained no other simpler substance. The Greek word for this is atomos, from which the word 'atom' is derived, and is how we view the modern elements.
    The most influential and popular theory was posed by Aristotle (ca 350 B.C.), and it was known as the Four Elements theory:
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    These elements interact with one another and even depend on one another (for example, wood, made from earth, will burn - create fire - but it requires air, and produces water in the process).
    All materials originate from one of the four basic elements.
    ...
    Four Elements {aristotle.jpg}
    The element mercury (Hg) was identified, and its extraction from cinnabar (its ore) was described, although this description was likely taken from older manusctipts from Egypt or Spain.

    The science of medicine also saw some advancements in this era, thanks to Hippocrates. He is what the modern "Hippocratic Oath" is named after. He also acted as an early pharmacist, prescribing willow bark as a painkiller.
    Chemistry in India, China
    {kanada-vaisheshika.jpg} Kanada Vaisheshika
    Interestingly, the concepts of atoms and elements were also described in Hindu and Chinese texts at approximately the same time as in Greece.
    The Hindu manuscripts revealed knowledge of many metals, and a "Four Elements" theory very much equivalent to Aristotle's - around 1000 B.C.!
    The Hindu philosopher Kanada Vaisheshika also derived a theory of the atom - matter being composed of indestructible spheres seven times smaller than the smallest mote of dust visible in a sun beam - around 500 B.C.
    In China, many metals were recognized, along with a "Five Elements" theory, circa 350 B.C.
    So, Greece was not alone in its advanced schools of thought concerning chemistry.

    Alchemy
    Chemistry was already studied and described by cultures such as the Persians, Chinese, and Hindu, but was essentially absent in Europe until the Middle Ages (circa 1100 A.D.). In these cultures, advances in distillation of acids, fermentation of alcohols, production of new metals (like mercury), and discovery of new elements had occurred. Most of this information evenutally filtered into Europe via trade and cultural mingling, and translation of Arabic texts.
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    6:58 am

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