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Introduction

The Lewis model of chemical bonding is one of the most powerful models in all of Chemistry. With the simple concepts of the octet rule and the sharing of an electron pair to form a chemical bond, we can predict what combinations of atoms and which molecular structures are likely to be stable or unstable. For example, we can predict that the molecular formula C 4 H 10 should correspond to a stable molecular structure, since it possible to draw a Lewis structure in which all four carbon atoms have an octet of valence electrons and each hydrogen atom has two valence electrons. In fact, we can even predict that there should be two such molecular structures corresponding to two different stable compounds, butane and methyl propane (often called isobutane). Lewis structures also allow us to predict the relative strengths and lengths of chemical bonds. For example, we can predict that in the molecule propene C 3 H 6 , one of the C-C bonds is a single bond and the other is a double bond; correspondingly, we can predict that the double bond is shorter and stronger than the single bond.

In general, for any molecule containing some combination of atoms of C, N, H, O, and any of the halogens (F, Cl, Br, or I), we can predict with confidence that the molecule will be a stable compound if we can draw a Lewis structure in which the C, N, O, and halogen atoms all have an octet of valence electrons. This is a very significant statement, since the overwhelming majority of the molecules of organic chemistry are composed of only these atoms. The converse is also generally true: if we cannot draw a Lewis structure in which these atoms have an octet of valence electrons, we will predict fairly confidently that a stable compound of that molecular formula probably does not exist. Note that “stable” does not mean “non-reactive.” In this context, “stable” means that the compound exists and can be isolated for long periods of time. Methane CH 4 is a stable compound which can be manufactured, captured, stored, and transported. However, it is also a reactive compound, reacting rapidly with oxygen gas in one of the most common combustion reactions in the world.

These are the reasons why we say that the Lewis structure model of covalent bonding is one of the most important models in all of Chemistry. However, like most good models, the understanding we get from the model comes with even more questions we might want to ask. In this Concept Development Study, we will address several of these, while others will wait for later studies. First, why does sharing a pair of electrons create a chemical bonding? More pointedly, what does it even mean to “share” an electron between two atoms? And why do atoms prefer to share a pair of electrons, rather than one or three? Of course, we’ve also seen that atoms can share more than one pair of electrons, creating double or triple bonds. We might have guessed that, with more electrons being shared, these electrons would repel each other, leading to a higher energy, but this is not the case. Why does sharing more than one pair of electrons produce a stronger bond?

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Concept development studies in chemistry 2013. OpenStax CNX. Oct 07, 2013 Download for free at http://legacy.cnx.org/content/col11579/1.1
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