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In looking at the structure of atoms to understand their properties, we have come up with two very powerful models. The first of these, the electron shell model developed in Concept Development Study 4, is based on observing the Periodic Law and the ionization energies of atoms. This led us to a model of the atom in which the electrons in an atom can be grouped together into “shells” with the electrons in a single shell seem to have similar energies. The second model is the quantum energy level description we observed in Concept Development Study 5. We observed that electrons in hydrogen atoms can only have certain specific energies, called energy levels. These two models seem quite similar. In both cases, it appears that the arrangement of the electrons in an atom can be understood by looking at the energies that the electrons can have.

But there are still many questions about how these two models are related. We developed the shell model by comparing the properties of different atoms, each with different numbers of electrons. We developed the quantum energy level model by looking mostly at hydrogen atoms, which each have only a single electron. We would like to know how the energy levels in a hydrogen atom are related to the electron shells in atoms with many electrons.

Perhaps the electrons in a single shell are in the same energy level, but we have not shown that. Even if we assume it is true, we still do not know what determines how many electrons can be in a single level. Without that, we do not know why each shell has a limit on how many electrons can fit. And if we don’t know that, then we don’t know why the properties of the elements are periodic.

To answer these important questions, we need to understand what it means for an electron to move about a nucleus. In the process of studying this, we will find that electrons move very differently than the ways in which we are used to particles moving. The results are surprising but they provide a firm foundation for understanding the Periodic Law of the elements.


In this study, we will assume that we know the postulates of the Atomic Molecular Theory and our measurements of relative atomic masses. We will also assume that we know that structure of an atom, with a tiny, massive, positively charged nucleus surrounded by a much larger empty space in which electrons move. The positive charge on the nucleus is equal to the number of protons in the nucleus and, in a neutral atom, is also equal to the number of electrons moving about the nucleus. We will assume knowledge of the concept of electron shells as a means of understanding the Periodic Law, which describes the chemical and physical properties of the elements.

From the previous Concept Development Studies, we shall also assume an understanding of Coulomb’s Law to describe the interactions of the protons and electrons in an atom. We will assume an understanding that light is an electromagnetic wave, meaning that, as it travels, the electric part of the light and the magnetic part of the light oscillate like a wave. And we shall also assume an understanding of the conclusions of our observations of the photoelectric effect. This means we understand that the energy of light is quantized into photons, or packets of energy, whose energy is proportional to the frequency of the light.

Questions & Answers

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 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
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 2012. OpenStax CNX. Aug 16, 2012 Download for free at http://legacy.cnx.org/content/col11444/1.4
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