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We assume an understanding of the atomic molecular theory postulates, including that all matter is composedof discrete particles. The elements consist of identical atoms, and compounds consist of identical molecules, which are particlescontaining small whole number ratios of atoms. We also assume that we have determined a complete set of relative atomic weights,allowing us to determine the molecular formula for any compound. Finally, we assume a knowledge of the Ideal Gas Law , and the observations from which it is derived.


Our continuing goal is to relate the properties of the atoms and molecules to the properties of thematerials which they comprise. As simple examples, we compare the substances water, carbon dioxide, and nitrogen. Each of these iscomposed of molecules with few (two or three) atoms and low molecular weight. However, the physical properties of thesesubstances are very different. Carbon dioxide and nitrogen are gases at room temperature, but it is well known that water is aliquid up to 100°C. To liquefy nitrogen, we must cool it to -196°C, so the boiling temperatures of water andnitrogen differ by about 300°C. Water is a liquid over a rather large temperature range, freezing at 0°C. In contrast,nitrogen is a liquid for a very narrow range of temperatures, freezing at -210°C. Carbon dioxide poses yet anothervery different set of properties. At atmospheric pressure, carbon dioxide gas cannot be liquefied at all: cooling the gas to-60°C converts it directly to solid "dry ice." As is commonly observed, warming dry ice does notproduce any liquid, as the solid sublimes directly to gas.

Why should these materials, whose molecules do not seem all that different, behave so differently? What are theimportant characteristics of these molecules which produce these physical properties? It is important to keep in mind that these areproperties of the bulk materials. At this point, it is not even clear that the concept of a molecule is useful in answering thesequestions about melting or boiling.

There are at least two principal questions that arise about the Ideal Gas Law . First, it is interesting to ask whether this law always holds true, or whether there are conditionsunder which the pressure of the gas cannot be calculated from n R T V . We thus begin by considering the limitations of the validity of the Ideal Gas Law . We shall find that the ideal gas law is only approximately accurate and that there are variations which do depend upon thenature of the gas. Second, then, it is interesting to ask why the ideal gas law should ever hold true. In other words, why are thevariations not the rule rather than the exception?

To answer these questions, we need a model which will allow us to relate the properties of bulk materials tothe characteristics of individual molecules. We seek to know what happens to a gas when it is compressed into a smaller volume, andwhy it generates a greater resisting pressure when compressed. Perhaps most fundamentally of all, we seek to know what happens toa substance when it is heated. What property of a gas is measured by the temperature?

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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 did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, General chemistry ii. OpenStax CNX. Mar 25, 2005 Download for free at http://cnx.org/content/col10262/1.2
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