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Thursday, October 24, 2013

Electronegativity



In order to understand the concept of electronegativity, it is necessary to take into account the following idea... The molecules are highly dynamic, and electrons are in constant motion around the atoms, representing the so-called "electron cloud". The movement of electrons around an atoms is directly conditioned by its characteristics. That is, if an atom has a greater ability to take over the electronic cloud, the electrons will be located predominantly on him. Electronegativity concerns exactly with this capability. Therefore, the more electronegative an atom is, the greater the portion of the electron cloud on it. Consequently, the more electronegative atoms tend to have negative partial charges, because at every moment there will be more electrons on them than on other atoms .

It is this asymmetry that is created in the distribution of the electron cloud that causes the molecules to become polar. Thus, in general , the presence of different atoms with different electronegativities in a molecule causes the molecule becomes polar, or at least the region where this happens to become polar .
In the case of biochemistry , since carbon and hydrogen have similar electronegativities, the regions of the molecules that contain only these two atoms are nonpolar , while the presence of oxygen, nitrogen , fluorine , phosphorus , etc., tend to render that region polar .

Wednesday, October 16, 2013

Music about the study of biochemistry (3)

What do you think about the idea to listen Frank Sinatra singing about biochemistry? Well, it is not the real Frank Sinatra that sings, but Dr. Ahern has adapted the famous song My Way and made another music about the study of biochemistry. It is for sure one of my favourite songs of Dr. Ahern! :)

Download the music here

My 'A'

And now, the course is done
Except for all that final testing
Dear friends, let’s have some fun
There surely won’t be much protesting

We’ve had a busy term
Addressing all the content swiftly
And so I sit and squirm
B-B three fif-ty

Exams, there’s been a few
Our averages were somewhat lower
The grades are all askew
I wish that Ahern would go slower

I studied hard each time
And even though my grades were iffy
Oh no, I did not whine
B-B three fif-ty

Yes it was tough
You knew it too
I memorized
My knowledge grew
And through it all
I did not frown
I thought it up
And wrote it down
I fought the fight
I hope it’s right
B-B three fif-ty

I laughed, I cried, I swore
Just as I did here on the first day
But since, the term is o’er
Let’s all go out for thirsty Thursday

I guess I have to face
The fact that I am not a swifty
But oh, I need to ace
B-B three fif-ty

The end arrives
Our grades are out
As I log in
To my account
I say some things
I truly feel
I hope I don’t
Have to appeal
There’s no dismay
I made my ‘A’

B-B three fif-ty
.

Wednesday, October 2, 2013