Lewis Electron Dot Diagrams HELP!!!

[DanceAndExpl]

Hey Guys,

 

I'm kinda new to chemistry, so excuse me if my questions sound really easy..

I need some help on Lewis Electron Dot Diagrams. How do you do them? They are apparently in my Chem exam next week, so any help would be greatly appreciated!

 

Thanxx

[foodchain]

You get to draw little dots on a piece of paper, these dots represent electrons in a configuration. Such as in carbon dioxide for instance, you would draw a carbon, and two oxygen, and then you would draw some or all of the electrons, or at least the electrons that your professor wants you to draw, these would most likely be the ones pertaining to whatever bonds happen to be going on at first. If you spend sometime reading on say electron configurations, you will be able to understand how a atom is modeled currently in regards to electrons and "shells" for instance, this can or does relate to your octet rule. The electron configuration will also let you understand the periodic table with more precision, such as electronegative for instance. The reason I throw all these random terms at you is simple, I took my first chemistry class, and it annoyed me all to heck because I knew that some mechanism or what not was going on in which the professor never spoke about, then I went on my own and looked at chemistry from a more physics perspective and things made much more sense. Some people can get by with just repeating and memorizing, but I needed to understand to actually work with it, and I think it pays off to do such.

 

Chemistry is a whole lot of stuff, it really is, such as knowing the erthyo form or the threo form is there in configuration or what not, and a lot of it simply is memorization in my opinion. The lewis dots are a very basic and vital aspect of this, and really its making a drawing of electron interactions in regards to elements for instance, such as how many electrons happen to be present for bonding in an s2p3, or does such matter in regards to environment and what other chemical its interacting with. Really there don’t seem to be a set pattern overall in my opinion.

 

Here, this link might help.

 

http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson38.htm

[DanceAndExpl]

Hey foodchain,

 

Thanx alot for your explanation and the link. i checked out the link and it pretty much explained everything i needed to know.

 

Thanx again

[Genecks]

For some of them, I tend to put the dots around the central atom in a type of symmetry (think 5-point star, 6-point star, 7-point star) if the atom does not follow the octet rule. In other words, I don't put them in four directions as I would for lewis structures that follow the octet rule. Afterwards, I try to redraw it according to VSEPR, but I typically just use lines (I don't go into the whole this-angle-is-bigger-than-that-one, which-is-why-it's-bold-and-that-is-dashed thing.)