Atomic Definition and 853 Threads

Sodium, = 11, has the ground state configuration [Ne] 3s^1 and is a “one electron” atom. Magnesium, Z= 12, is a “two-electron” atom. Write down its ground state configuration and possible term values. i think i get the right answer but I am having a couple of issues: my answer: ground...

What is the physical process common to both the emissions of atomic x rays and nuclear gamma rays? is it photoelectric.. or the inverse.

why the universe is a bad model to describe the atomic world? sun=nucleus planets=atoms they orbits they spin like subatomic particles they have magneticfield I mean anything you get from the atomic world, you have it in the macro world.

Hello, I've been wondering about the velocity of hydrogen electrons. I've read that 242,000 m/s was the correct velocity, however, I thought electrons would travel at c. How does one calculate this number? Thanks in advance.

Homework Statement Three-energy levels atomic gas is confined in the thermostat and subjected to an external radiation field (w=e3-e1 ). Determine occupation probabilities of the energy levels and the conditions for a coherent spontaneous radiation. Homework Equations The Attempt...

If an atom with more protons have tighter electron orbitals than atoms with fewer protons, why doesn't the "atomic radius" decrease up the periodic table? Instead it increases, why is this?

Hi all, I'm looking at the ALD process for a uni project and could do with some clarification on a couple of points. Does anyone have any idea what the effect of non-uniform substrate heating would be? Would it harm the chemical bonding and cause ablation? I can't seem to find out from...

What is being discussed when frequency is used to describe atoms? Or maybe I should be thinking nuclear oscillations...In other words, the wave function of what?

Hi guys. I was wondering what are your thoughts on how the atomic bomb has made an impact in science?

To initiate fusion, it says that the nuclei of each atom need to come into contact. And these atoms therefore need to be fully ionised for this to occur. Does FULLY ionised mean that the atoms have lost ALL their electrons? thanks :)

Hi all, I have recently been listening to one of Professor Richard Wolfson's physics lectures, and a question has occurred about an aspect of general relativity; that time 'slows down' in strongly curved spacetime. In this particular lecture, he mentions an experiment done some years ago in a...

Hey just need help regarding a few questions. 1. Which is more stable, C 2s or C 2p? Why? Choose the best answers from below: (a)higher shielding (b) lower shielding (c) lower n value (d) lower l value 2. Which is more stable, Ar 5p or Ar+ 5p? Why? Choose the best answers from below: (a)higher...

I did an experiment to calculate the cross section for capture, loss, and ionization for a 05+ projectile on an 02 target at 16, 24, and 32MeV. We used a tandem to produce the the beam, and a time of flight method (ToF) to determine the fragments. (We used the known Ne and He spectra as a...

Hello, can someone explain how a line spectrum works. How do they provide evidence of energy levels in atoms? I would have thought that energy levels are to do with a different concept of Bands (Valence, Conduction) so how does a line spectrum provide evidence? :confused:

Can someone explain to me why different terms arising from a particular electron configuration have different energies? For example, for carbon in the configuration 1s^22s^22p^2 three terms arise, 3P 1D and 1S. These three terms have different energies but I don't understand why. The electron...

Please explain the phenomena of reflection at atomic level ? We know that on reflection a phase change of pi occurs i/e phase difference b/w reflected & incident beam is pi , explain this phase change of pi at atomic level ? What is actually meant by phase change atomic level ?

Homework Statement Two identical spin 1/2 particles of mass m exist in a one dimensional harmonic oscillator potential \frac{kx^{2}}{2} where x is the position coordinate and k is a constant. The particles interact with eact other with a potential W\delta(x-x'), where \delta(x-x') is a Diract...

Homework Statement a)what property of graphite is the result of the presence of delocalized electrons? b)what is the reason for the generally low melting point of group I A metals as compared with the high melting points of metals in the center of the transition series? The Attempt at...

Dear experts - I'm writing a novel in my spare time, and would appreciate some help with a little bit of research. Some of the story is set in the distant future, where super strong materials are available. My problem is that I don’t know how to describe these super materials. I want to...

Homework Statement Find all possible values of L, Lz, and θ for an electron in a 3d state of hydrogen. I confuse it long time.. explain me please..

Homework Statement I'm taking a metrials class, and there are 2 questions I'm not sure how to do. I would see the professor first, but he refuses helping students until the assignments is submitted. 1) A circular tungsten (W) wire that is 0.1m long and 1mm in diameter has 9V dropped across...

how can you explain atomic nuclei. liquid, charged, solid what? and there are some words about nuclear radius rn, rp and rc. what is the meaning of these words. all these data are experimental results or calculated. one is "atomic data and nuclear data tables, vol 71, no. 1, 1999, G.A. Salazar...

First I'm not a native English speaker so sorry for grammar errors . Ok let's start my hobby is to learn things and I tried to study relativity while I where reading some example of time dilation in atomic clocks. However I remembered something the speed of a electromagnetic wave is equal to...

May someone please explain what were some problems with the Bohr model of the atom. I found a few things on Wikipedia, but I being a beginner in the Physics curriculum do not fully understand how it all ties together. If there is a link to this topic in the forums, please do tell. Thanks.

Hello I didn't get something about the AO. i.e the electron configuration of C is 1s² 2s² 2p² . So we know that at the 2nd shell this has 4 electrons, 2 in s orbital + 2 in the p, right? How do we find out how the 2 electrons of p are spread in the px, py, pz? Thank you, Panos

for n=2 & l=1 we have P orbital for which magnetic quantum no. can take values -1,0,1 , now in p orbital we have 2Px, 2Py &2Pz each corresponding to vale of m like 2Px for m=-1 and so on , is this correct or 2Px can be represented by 0 0r 1 also .

1. Determine all terms in the configuration 4s^2 4p 4d in neutral germanium The answear is Singlett P,D and F Tripplett P,D and F But I don't really understand what singlett and tripplett means, and how do I know which tearms there are?

Is there a formula that can be used to find the half life of an atom? If so, what is it?

1 u = 1/12 of the mass of a neutral carbon atom with nuclear charge 6 and mass number 12, 1 u = 1/12 * 12.000000 /NA * 0.001 where NA is avogadro's number. I wonder is it that the scientists purposely make one mole of carbon-12 to be just 12.00000g? I want to ask is it when the...

I am doing some research on atomic clocks. From what I have read, I understand that in Rb atomic clocks you: -optically pump a cell of Rb, so that the electrons are all in a single hyperfine state -subject the cell to microwaves of appropriate frequency, so that the electrons will be...

A nuclear warhead for example doesn't seem to take a lot of energy to make, however it outputs massive amounts of energy in an instant. Why isn't this more energy out than in and why doesn't it break the law of conservation of energy? I think the answer is going to have something to do with...

Homework Statement Suppose that a human head is a sphere with the bone thickness 10% of the radius of the head. Find the fraction of the volume of the head occupied by the brain. Make a similar estimate (forget about factors of pi) in the N-dimensional space (d = N) in the limit N ->...

my question is : How would you make a 1, 3, 5, 7ppm solution from a 100ppm solution? do i just just this formula: C1V1 = C2V2 to calculate the amount i need? for example, for 5ppm solution => (5ppm) V1 = (100ppm)V2 so for V1, I just choose my final volume to be whatever i like... like...

all says electrons rounds the nucleus and revolves in its own axis if so in which direction electrons rounds the nucleus?

i have a big problem while i m trying to measure Cr with flame with Aanalyst 200 i m following the guidelines of perkin elmer. i m using a rich yello flame 4.5/10. i have made some standards 0.2, 1,2,4 with 0.2% nitric acid. i m doing calibration and when i finish i have noticed that the...

Ok, I just posted this in the advanced forum, but looking at some of the topics on there my question might belong in here instead.. I understand Rutherford proposed that electrons orbit around a central nucleus. However, since accelerating charges produce electromagnetic radiation, the...

I understand Rutherford proposed that electrons orbit around a central nucleus. However, since accelerating charges produce electromagnetic radiation, the orbiting electron should lose energy via E&M and spiral into the nucleus. But my question is: How do I calculate the time it takes for the...

Homework Statement The ground state electron configuration for phosphorus, which has 15 electrons, is 1s^2 2s^2 2p^6 3s^1 3p^4 1s^2 2s^2 2p^6 3s^2 3p^3 1s^2 2s^2 2p^6 3s^2 3d^3 1s^2 2s^2 2p^6 3s^1 3d^4 1s^2 2s^2 2p^6 3p^2 3d^3 Homework Equations The Attempt at a Solution...

Hello all! I realize these questions may have been more appropriately posted in another forum, however for their application I will use interstellar space. 1st: As I just read a few threads down, solar wind consists of protons and electrons, overall the charge of the sun (or any mass)...

Homework Statement Please help me calculate the center of mass of the polymer (radius) from atomic coordinates (more than 2000) given in Armstrongs. Can anyone help with the formula? I need to calculate the radius of gyration of the polymer. Thanks. Homework Equations The Attempt...

On the P.T.E., the atomic mass number of an element gives the number of protons and neutrons in its nucleus, ie. the number of particles in its nucleus. But this number also gives that particular elements molar mass, correct? eg. For carbon, it has 12 particles in its nucleus, and its molar mass...

i'd like to know what is the number of atoms per unit length for an atomic chain in the [1 1 1] direction of a BCC structure. i can figure out the unit length, however I'm not sure how many atoms to use. Is it 1/8+1/8+1? That means 1/8s for the two corner atoms and 1 atom for the middle? or...

The Little Boy bomb dropped on Hiroshima was very inefficient in terms of the amount of uranium fissioned. My questions are: What happened to the unreacted uranium and does it still pose a problem? I'm sure for most of you on this site this is an extremely easy question, but I am new to this and...

Big Question! In my chem class the teacher doesn't explain very much so I decided to see if this site may help. Ok, so my question is: The atomic mass of an element X is 46.80. A 35.78 gram sample of X combines with 84.10 grams of another element Y, to form the compound XY. Calculate the atomic...

Hi I was wondering if anyone could give me info about atomic electric dipole moment at a very fundamental level (fenomenological, basic quantum), I do not seem to find it when I google =( My Aim is just to understand van der Waals binding in solids a little bit more.

I need help with these two questions: 1. Electron diffraction can be used to investigate both the arrangement of atoms and the dimensions of nuclei. Explain how changing the energy of the electrons can be used to achieve this. And... 2. Uranium has atomic number 92. Two of its common...

https://www.physicsforums.com/showpost.php?p=899393&postcount=4 describes why photons are slower in some medium. After reading it, I've few more questions: When a photon hits an electron, if it absorbs the photon and reemits, here's my questions: 1. How does refraction possible? The...

i heard that there is an idea (i don't know if it's true) that we can make ANY ELEMENT radioactive! and i thought "wtf"!

Hello all, I'm having a little trouble researching this as I'm not sure what the exact field of study is called, googling Atomic Vibration doesn't come up with much. Basically I am looking to disprove a theory (with hard science) that thoughts can affect the crystalisation of water. The...

I can't understand how both the atomic weight of one atom of an element and the weight in grams of a mole of that element are the exact same thing. For example helium has an atomic mass of 4.0026. That was obtained by adding the amount of protons and neutrons in a helium atom together. On...