Chemical Bond: Force of attraction between any two atoms
This attraction overcomes the repulsion of the two positively charged nuclei
Valence electrons are the ones responsible for chemical bonds
Lewis Symbols
Lewis symbol (Lewis structure) - a way to represent atoms using the element symbol and
valence electrons as dots
As only valence electrons participate in bonding, this makes it much easier to work with the
octet rule
The number of dots used corresponds directly to the number of valence electrons located in
the outermost shell of the atoms of the element
The four sides around the atomic symbol can each have two dots for a maximum of eight
(octet)
1
,Using Lewis Symbol
Place one dot on each side until there are four dots around the symbol
Now add a second dot to each side in turn
The number of valence electrons limits the number of dots placed
Each unpaired dot (unpaired electron of the valence shell) is available to form a chemical
bond
Principal types of chemical bonds
Ionic Bonds: A transfer of one or more electrons from one atom to another (Forms
attractions due to the opposite charges of the atoms)
Covalent Bonds: Attractive force due to the sharing of electrons between atoms
2
,Some bonds have characteristics of both types and not easily identified as one or the
other
3
, Lewis Structures & Polarity
A molecule is polar if its centers of positive and negative charges do not coincide
Polar molecules when placed in an electric field will align themselves in the field, non-polar
molecules will not
Molecules that are polar behave as a dipole (having two “poles” or ends), one end is
positively charged the other is negatively charged
Use the following symbol to denote the polarity of each bond
Determining Polarity
Molecules that have no lone pair on the central atom, and all terminal atoms are the same are
non-polar
Molecules with one lone pair on the central atom are polar
Molecules with more than one lone pair on the central atom are usually polar
Si - Cl: polar
4
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller williamboutros. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.49. You're not tied to anything after your purchase.