Tuesday, December 14, 2010

Poly Atomic Ions are EVERYWHERE...

In makeup foundation...

1) Zinc Oxide

2)  Iron Oxide

In Advil...

3)  Potassium

In eyedrops...

4)  Magnesium Chloride

5)  Calcium Chloride

6)  Potassium Chloride

7)  Zinc Chloride

8)  Hydrochloric Acid

In Hydrogen Peroxide... non other than...

9)  Hydrogen Peroxide!!

In scented powder...

10)  Magnesium Carbonate

*To see the other 10 see Michelle's blog!!

Thursday, November 11, 2010

Midterm Review Question #8

8) Explain the difference between chemical properties.  Describe some of the physical and chemical changes involved in cooking.

    -Produces matter different from original composition in a chemical change that can't be restored to                        
original state.

    -Can be observed and measured without changing substance's composition and can be restored to original state.

Cooking Example:
    -When baking a cake a key ingredient is baking soda which causes a chemical reaction enabling the cake to rise.  This is chemical because the cake can never be turned back into the same batter.

Tuesday, October 5, 2010

Rutherfords Gold Foil Experiment

In 1909 Rutherford's gold foil experiment changed the way people viewed the atom forever. The experiment was conducted at the University of Manchester by Hans Geiger and Ernest Marsden under the direction of Ernest Rutherford. Rightfully so, this experiment is also known as The Geiger- Marsden experiment. This was revolutionary in that it proved for the first time, the existence of the atomic nucleus, thus killing the idea of the plum pudding model. Geiger, Marsden, and Rutherford's work will be studied forever.


The Plum Pudding Model composed by J.J. Thomson said that negative electrons were placed throughout and everything else (the pink) was positively charged "pudding" to balance the negative electrons.

The experiment was set by placing a particle emitter that would shoot particles made by radioactive decay of radium directly to a thin sheet of gold foil. Gold Foil was used because it is inert and malleable. In order for the particles to go through the material, it had to be really thin and gold was the perfect metal. Around the particles that would shoot toward the gold foil there was a circle of zinc sulfide which would detect when and where the alpha particles would deflect.

Rutherford hypothesized that the particles would pass straight through the foil or at most only deflect a couple of degrees. If this had occurred, it would have measured the distribution of charge through the "plum pudding" atom. This assumption was based on the theory that positive and negative charges were spread evenly through the atom, thus making their forces weak allowing for very little, if any deflection.

What ended up happening was the slit in which the particles were passed through, when made larger (greater than two nanometers), more particles were able to get through and the majority of these particles passed straight through the foil. Only one out of 8,000 were deflected at very dramatic angles. These angles were even greater than 90 degrees and in some cases the particles completely back fired.

In conclusion, this allowed Rutherford the prove J.J. Thomson's plum pudding model false.  Rutherford found that an atom is mostly made up of empty space with a concentrated charge in the middle.  He was able to conclude this because the majority of the particles passed through the empty space of the atoms and were not noticeably deflected, but the positive charge of the particles would repel against the one focused area of positive electrons in the atoms.  The focused and concentrated area that was discovered was named the nucleus.  Rutherford along with Geiger and Marsden came up with the following model of an atom.  It is because of these scientist curiosity that the model of an atom kept evolving and became more accurate.


<a href="http://www.wordle.net/show/wrdl/2530981/rutherfords_gold_foil_experiment" 
    title="Wordle: rutherfords gold foil experiment"><img
    alt="Wordle: rutherfords gold foil experiment"
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Thursday, September 9, 2010

The Physical and Chemical Properties of a Penny

istockphoto_2992953-lincoln-penny-2007-on-white-background.jpg         The penny, something we use everyday, but never take the time to examine.  A penny has many properties, both chemical and physical, that are not always apparent the the naked eye.  Based on the year the penny was made, there are a couple factors that that could cause different results.  For instance if the penny was made between 1944- 1982, then it is made of 95% copper and 5% zinc, while if made after that, the penny will be made of 2.5% copper and 97.5% zinc.  For experimental purposes, I chose to focus more on the penny made before 1982 that had a larger amount of copper in it.  The penny possibly the most simple and basic form of money has more properties than one would have ever thought.

Physical Properties

All of the properties listed below are physical because the compound itself changes, but nor the chemical composition.
  • Weight:
    • Before 1982: 3.1 g
    • After 1982: 2.5 g
  • Volume: 360 mm3
  • Color: A copper color that loses its sheen over time.
  • Circumference: 19mm
A smashed penny's weight and volume would stay the same, but it circumference would be changed.
  •  Smell: A copper/ iron smell similar to blood

Chemical Properties

All of the following properties are chemical because they involve a chemical reaction that can never be undone.

  • By putting a penny in bleach, along with cleaning the penny and removing some of the rust, dirt, ect., it produced a gritty white material on the penny.

  • By putting a penny in water it will eventually rust causing a chemical reaction.

  • By putting a penny in jewelry cleaner it removed most of the rust, dirt, and made the penny shinier.
The older penny's results were much
more noticable. The cleaner brought the penny
 back closer to its original state.

  • When i put a penny in coke there were signs that corrosion had started.  Based on my research if i had a longer period of time for the penny to sit in the coke the corrosion would be so great that the penny would dwindle down to nothing.
The older penny was the one that had shown the most progress thus far.

  • When I covered the penny with vinegar and left it over night, a green copper acetate formed much like the one on the Statue of Liberty.