Atomic Definition and 853 Threads

I've drawn up a simple system to help with my question. Suppose we prepare an atom in an excited state (| 4 \rangle in the figure), and it can spontaneously decay to the ground state (| 1 \rangle ) through either of two intermediate states (| 2 \rangle or | 3 \rangle ). Is the probability...

Hi All, I would like to ask a question on Purcell’s EM textbook on atomic polarizability. On page 362, Purcell put the relation: \underbrace {\frac{{\Delta z}}{a}}_{{\rm{dimensionless}}} \approx \underbrace {\frac{E}{{e/{a^2}}}}_{\frac{1}{{{\varepsilon _0}}}} I suspect that it...

An inflated smooth toy balloon is coated with a single atomic layer of aluminium. Esitimate the mass of Al that would be required. The density of Al is 2.7 x10^3kg/m^3 and its molar mass if 27 grams for mol. I assusmed the balloon was a sphere of radius 10cm, found surface area then...

Hi all, To my knowledge hybridization of atomc orbitals occurs only between orbitals in the same atom, with similar energies, in order to produce new atomic orbitals, identical with the same energy, to make chemical bonds with other atoms. There are sp, sp2, sp3, etc... possibilities. My...

Hi I can't seem to find any recommendations for a good atomic physics book on this site. What would you guys recommend? The level is senior undergraduate/beginning graduate physics. I have C.J. Foot's "Atomic Physics" already. Any help will be appreciated. Niles.

Homework Statement Consider phonons propagating on a one-dimensional chain of N identical atoms of mass M interacting by nearest-neighbour spring constants of magnitude C. Show that the Debye frequency can be written as w_{D}=\pi \left(\frac{C}{M}\right)^{1/2}. Homework Equations The...

Homework Statement Calculate the smallest angle (in degrees) that the total angular momentum of an atom in a 7D term can make with the z-axis. Homework Equations 2S+1LJ The Attempt at a Solution Given that the total angular momentum of the atom is defined by the quantum number J...

Hi All, I have a thought that I had a while ago and wanted some advise/feedback etc My thought was as follows: All atoms have their own specific vibration, if one was able to match this vibration or its oppisite then the bonds that hold this atom together would break apart. Kind of...

i asked to find the number of Atomic orbital of: principal quantum number(n) and the orbital Angular momentum quantum number (L) of the orbital 2s tell me if i correct n=2 and the Angular momentum L=0 ? and in the orbital 6f n=6? and L=3? thanks.

Hi, I know nearly nothing about physics, I'm a mathematician working on a computer program. Anyway, I have to write a program and my boss suggested that I use atomic units and that at the end of the program I can "scale up" to natural units if desired. I tried to read up on these units, but...

Here is a problem I have. Not really sure where to start. I'm not looking for the answer, I just want someone to point me in the right direction. A hypothetical element X has three isotopes: 40X, 41X, and 42X. Their abundances are 72.00%, 9.00% and 19.0% respectively. What is the atomic mass of...

Homework Statement Natural carbon consists of two different isotopes. The isotopes have different masses, which is due to different numbers of neutrons in the nucleus; however, the number of protons is the same, and subsequently, the chemical properties are the same. The most abundant isotope...

I guess this is a FAQ, but since it constantly confused me, I'm just going to ask anyway. Two ways of exciting atoms, shoot a beam of photons and let atoms absorb them, or shoot a beam of electrons, and let atoms collide with them. However, for the excitations to happen, the former case...

Say there are two atomic clocks floating through space, both completely stationary with respect to each other. They are exactly synchronized, and not under the influence of any significant gravitating bodies. One is significantly farther ahead in the direction of motion than the other, but they...

Attached are two diagrams. One describing Moore's law, the other describing the development of atomic clocks since the 50's. Is there a connection between these diagrams, not in the strict graph-math equivalence sense, but in the sense, that conclusions regarding atomic clocks' future accuracy...

Attached are two diagrams. One describing Moore's law, the other describing the development of atomic clocks since the 50's. Is there a connection between these diagrams, not in the strict graph-math equivalence sense, but in the sense that conclusions regarding atomic clocks future accuracy...

Homework Statement So the question is I have to use some trial function of the form \sum c_if_i to approximate the energy of hydrogen atom where f_i=e^{-ar} for some number a (positive real number). Note that r is in atomic unit. Homework Equations Because r is in atomic unit, I think I should...

The g-factor of an electron (-2.002) added to the g-factor of a proton (-3.826) approximately equals the negative g-factor value of a proton (5.585). Ge + Gn = -5.828 Is there any significance in this?

Homework Statement ...Consider a diffuse gas cloud that contains carbon monoxide (CO) molecules... What are the radio wavelengths (in cm) and frequencies (in GHz = gigahertz = 109 Hz) corresponding to transitions between the ground state, the first excited state, and the second excited...

Homework Statement Estimate the diameter of an atom of a substance whose density is 103 kg/m3Homework Equations Vatom = 4 \pi r3 /3 \sigma = m/V The Attempt at a Solution I have attempted a few different things, but I always come out a variable short, and although they question says estimate...

Hey all, This is actually my first post on this forum but I have been reading it for a few months now. Anyway, I'm sure the title of this thread might be confusing but this question has been bugging me for years now and I'm sure I'm missing something quite elementary. My question has to...

Why atomic mass doesn't match the number of protons and neutrons in it? for example mercury mass is 200 gmol but it has only 80 protons and 80 neutrons. From where does 40 gmol come from?

Homework Statement The first few lines of the Balmer series for atomic hydrogen lie at the wavelengths λ = 656.46, 486.27, 434.17, 410.29nm, ... Find a value for RH, the Rydberg constant for hydrogen. The ionization energy I is the minimum energy required to remove the electron. Find it from...

So my Atomic Physics professor today was talking about some called the "Virial theorem" in relation to Bohr Model of the H-atom, which in my 5 years of college physics I had never heard of >_<;; . It turns out that I had seen equations that use concept of the Potential "==" Kinetic Energy, I...

My book defines the atomic form factor as \int dV n_{j}(\vec{r})e^{-i \vec{G} \bullet \vec{r}}. where n(r) is the electron density of the jth atom at r, and G is the reciprocal lattice vector. It says the above expression is equal to 2 \pi \int dr r^{2} d(cos \alpha) n_{j}(r) e^{-iGr cos...

Hi, I am wondering what sort of frequencies electrons have in atoms at different energy levels. When I say frequency, I'm *not* talking about the frequency of the orbiting motion. I am wondering what the electron wave oscillation frequencies are at the different energy levels. A couple...

Hello, this might be a trivial question for many of you. I would like to know what are the simplest phenomena/experiments, if any, (and perhaps the first historically) that contradict the assumption that subatomic particles like electrons, protons, neutrons..., can be thought of as "small...

Hi Guys, I have a bit of a problem with some course work please help: The question is: Determine the atomic fractions Xc and Xo (carbon and oxygen) for the following gas composition at room temperature: 50% H2, 30% H2O, 20% CO2 I am sure you need to work out the partial pressures for...

I find it remarkable that physicists are sometimes willing to take “the anthropic principle” seriously, in any of its forms, since its explanatory power at the physical level is nil. Okay, say the universe is structured the way it is just so it can support conscious observers. That tells us...

Hi, So according to the Thomas-Fermi theory, the formula for atomic radius is R=Z^(-1/3)*(hbar ^2)/m*e^2. (in other words Z^(-1/3) times the Bohr radius) While the total energy has a Z^(7/3) dependence. I need to get this from dimensional analysis. I can get the dependence on h, m, and...

Hii, I was wondering whether there is any correlation between the energy eigenvalues of a single atom (say He) with the electronic band structure of a collection of He atoms. for example, for He atoms the lowest energy would be the ground state, with 2 electrons. So will the lowest band for a...

Homework Statement I'm writing a paper on the Manhattan Project, and as part of this paper I am asked to show: "... calculations that can help illustrate the explosive power of an atomic bomb compared to ordinary explosives."Homework Equations Released energy per fission: Q = \Deltam * c2 The...

"Told science" Hi guys! I am going to take part in a literature project, which is called "told science". You have to write a scientific eassy such as a story. For this year I was wondering to write down something about the atomic bomb. My idea was to write the best quotation on atomic bomb in...

What is meant by nuclear atomic model?

Hello, In Max Borns book Atomic Physics, in chapter 1, section 3, it reads http://books.google.ca/books?id=NmM-KujxMtoC&lpg=PP1&ots=yDc9g9R8Ky&dq=max%20born%20atomic%20physics&pg=PA5#v=onepage&q&f=false" "If we think of the molecules as billiard balls every molecule when it strikes the wall...

Like, let's say substance A, in the sun, is very hot. After the sun goes down, it stays hot, but after awhile it becomes cold. Element B, in the sun, is also very hot, but after the sun goes out, it basically becomes cold immediately. Why is this?

This is rather a straightforward question I believe, but somehow I'm not sure about the wording of it... Homework Statement Calculate g value (Landé g factor) for sd configuration in jj coupling. Homework Equations g = 1 + \frac{J(J+1) - L(L+1) + S(S+1)}{2J(J+1)} The Attempt...

1. Isn't it the Bohr atomic theory is proven incorrect, why some textbook even that publish in 2007 still use it to explain about electron movement? Isn't it should be using SPDF theory? 2. What is meant by satellite valley? 3. How is electron move in atom if not circulate in an orbital? 4...

Homework Statement 1. The Table below lists the isotopes of Pb and their percent by mass: Isotope % Mass 82p, 122n 1.37% 82p, 124n 26.25% 82p, 125n 20.82% 82p, 126n 51.55%(a) Using these data, calculate the approximate atomic mass...

Hi My textbook states that say 50 amu/atom = 50 g/mol. Which does not really make any sense. I am not sure how to get the atom unit. Since on wikipedia it says u = Molar-mass/Na Molar-mass(g/mol) = u*Na I also know that 1gram/Na = 1u

Homework Statement An equilibrium ore mixture has an atomic ratio for \frac{U-235}{Pa-231} = 3.04x10^{6} Find the half-life of U-235 from the data. The known half-life for Pa-231 is 3.28x10^{4} years Homework Equations For secular equilibrium \frac{\lambda_{2} N_{2}}{\lambda_{1}...

Homework Statement Calculate atomic magnetic moment of Ni in Bohr magneton. Given that atomic weight is 58.69, density is 8.91 g/cm^3 Atoms/moments are fully aligned in the field direction and have magnetization of 4.84 x 10^5 A/m Homework Equations The Attempt at a Solution...

Can the density of gas be changed for good, or is the change just temporary? And what increases density in gases?

Hi, I'm having problem about Atomic energy levels. Who can help me find Images about Atomic energy levels diagrams of chemical elements. Thanks^^. Example: Atomic energy level diagram of Hg: [PLAIN]http://ca8.upanh.com/15.290.19566358.Z7p0/fig1.gif You can contact me. I'm Hoang An

hi i was wondering if anybody could help me? for calculating if there's a missing part how do i solve it ? i have a picture ... how would i figure out the third part ..?

Just want to make sure if I have this correct and to ask a question, If you pass an electric field through an atom, it polarizes it the atom with a dipole moment p = \alpha E where is a constant of polarizability and E the electric field. Because of the electric field, the nucleus moves in the...

Homework Statement 5 The energy levels of a molybdenum atom are approximately: K shell ….. – 20.00 KeV L shell …... – 2.52 KeV M shell …... – 0.23 KeV i) Estimate the energy of the Kα, K\beta and Lα x-ray emissions. ii) What are the wavelengths of...

Hi all, What are the common atomic radii that are used for drawing chemical pictures? Is it the ionic or calculated or? Thanks.

Homework Statement Give the full designation (e.g. 3P0) for all possible singlet, doublet, triplet and quartet S, P and D atomic states. The Attempt at a Solution I don't understand this question at all! Up to which values does the angular momentum (supscript) and multiplicity...

Homework Statement What is the difference between nuclear fission and nuclear fusion? After answering the question proceed on to answer the next question Between Hydrogen Bomb and Atomic Bomb, which bomb causes more damage. provide you answer with reasons. Homework Equations Nuclear...