Tuesday, December 7, 2010

Did I really just swallow that?

On the ingredients list of the now-decipherable Centrum Multivitamin/Multimineral Supplement, I ran into some ionic compounds that were understandable.  All ten listed below were on said ingredients list; it really is a multi-ionic compound supplement!

1) calcium carbonate

2) magnesium oxide

3) potassium chloride

4) cupric [copper (II)] sulfate

5) manganese sulfate

a) manganese (II) sulfate

b) manganese (III) sulfate

6) nickelous [nickel (II)] sulfate

7) zinc oxide

8) stannous [tin (II)] chloride

9) potassium iodide

10) sodium selenate

You can find ten more examples on my partner's blog.  Click here

Tuesday, November 9, 2010

Test Review: #3

3.  Looking at the trend in first ionization energies across period 3, there is a sudden unusual dip with Al and S.  Explain this.

Well, at first we look at this problem and say what, this doesn't make sense.  Ionization energy is supposed to increase across periods, not drop!  Well, there just so happens to be an anomaly in this all too perfect trend.  To better understand this question, look at the visual display of first IEs below.

Also, to take a look at another representation, click here

Now, what the problem is asking for is this: why does IE drop from Mg to Al and P to S (you can ignore Si)?

Well, the answer in a nutshell is that it is a matter of stability.  Look at the orbital filling diagrams below:

Let's look at the first pair: Mg and Al.  Mg has a completely empty 3p sublevel while Al has a lone electron floating in that same corresponding sublevel.  Mg has added stability because of its completely filled 3s sublevel and it wouldn't benefit the atom if one of those electrons were ripped away.  Taking away an electron from Mg would be ruining the added stability of having a completely filled sublevel.  Al, on the other hand, would benefit from losing an electron because then its 3p sublevel would be completely empty.  An empty sublevel is more stable than one with a single electron roaming around.  That is why, if you steal one of Al's electrons, more stability would be added.  So, because Mg avoids ruining the stability it has and Al aims to get the stability Mg has, there is a dip in IE.

The next pair, P and S, can be explained with the same reasoning.  P has a half-filled 3p sublevel and S has 4 electrons in that same sublevel.  Again its about stability.  P  has already achieved stability by only having 2 electrons in 3 orbitals but S aims to have 3 electrons in 3 orbitals.  So, for the matter of stability again, P avoids ruining its stability while S benefits from gaining P's.  Therefore, there is a dip in IE.

*The easier it is to remove an electron (in other words, the more an atom tries to lose an electron-for stability in this case), the less energy is required to remove it.


The visual display of IE:

Second display:

Sunday, October 3, 2010

The Discovery of the Neutron

We have already talked about the discovery of the electron by J. J. Thompson.  However, today, we will be talking about the discovery of the neutron, by James Chadwick.  So I hope you're ready because this is quite the experiment.  Click on the link if you dare to proceed into the world where physics meets chemistry, but first, read what is below:  The Discovery of the Neutron
Click More and then Fullscreen to see the Prezi.  To advance through the slides, press the Play button.
All numbers in parentheses seen near or around something (not in circles, but rather parentheses) are denotations of footnotes.  The citations of these are at the end, in the slide entitled bibliography.

Monday, September 6, 2010

Milk isn't just good for drinking...

     Milk is the object that I chose.  I chose it because everyone has it in their houses, it is safe to experiment with, and it provides a blank canvas on which I can test ideas.   was very curious to learn about its properties for the reason of its perishability.  This attribute was intriguing and is the reason for me choosing it.  I observed some physical qualities.  I also experimented with some "grocery store" chemicals.  Every chemical property that I listed was learned because of my own experiments.
     The milk you will be seeing is not something that you would put in your cereal.  In fact, I would never even think about eating the concoctions that I created.  Some will appear disgusting, but there is no need to cringe, it is all in the name of science.  To see what I did and learned, click on the word "PREZI" below.