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Why should these materials, whose molecules do not seem all that different, behave so differently? What are the important characteristics of these molecules that produce these physical properties?

One of our first efforts at making a connection between molecular properties and macroscopic properties is the development of the Kinetic Molecular Theory. Among the very most important concepts in Chemistry is that atoms and molecules are constantly moving. These movements have a lot to do with how and when the atoms and molecules react with each other. Also among these very important concepts is that the movements of atoms and molecules are related to their temperature. We shall see that a higher temperature corresponds to faster molecules with more energy. Knowing this will help us understand a lot of Chemistry, including how chemical reactions are affected by temperature and energy.


Since we wish to relate macroscopic properties to molecular properties, it is worth remembering what observations and conclusions we have already made about each type of property. In this study, we will focus mainly on the observations of gases which led us to the Ideal Gas Law. We will assume that we have made measurements of the pressure of a gas under different conditions. From these, we know that the pressure of a fixed sample of gas is inversely proportional to the volume in which the gas is contained, meaning that if we reduce the volume of the gas by compressing it, the pressure will rise. In a similar way, we know that the pressure of a fixed sample of gas in a fixed volume will increase in proportion to the temperature, provided that we measure the absolute temperature in Kelvin. And finally, the pressure of the gas kept at fixed temperature is proportional to the “particle density” of the gas, which is the number of gas particles (atoms or molecules) divided by the volume of the container.

We have also learned a great deal about molecular properties that will be useful in this Concept Development Study. We know that different atoms have different electronegativities and that, as a result, when these atoms are bonded together, the electron pair sharing is not equal. This can cause the molecule to have a molecular dipole moment. We also know about the geometries of molecules and that a symmetric molecule may not have a dipole moment even if the bonds in the molecule are polar.

There are a few results from Physics which are important to our work. The first of these is that pressure P is the force exerted F divided by the area A on which it is exerted:

P = F A

This sounds complicated but is actually commonly observed. Think of the differences you see when force is applied to a small area, like the head of a nail, instead of being applied over a large area. For example, a stack of books piled on a desk creates a downward force due to gravity, but that force is applied over a large area, which is the size of the bottom book in the stack. This means that it does not generate that much pressure, so the books have no effect on the desk. However, if the stack of books is somehow piled on top of a sharp nail, the pressure created is very high because the force of gravity has been applied to a very, very small area, namely the point of the nail. This high pressure means that the nail may penetrate the surface of the desk. The force applied in either case is the same, but the pressure is quite different when the stack of books is placed on the nail.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
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.
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
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
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
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
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.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar 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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