Atoms Definition and 880 Threads

Hi guys, I know that if we consider a basic atomic model ( not considering quantum mechanics here) that an atom is mostly empty space ( 99.99999%) or something like that. But how about the space between the atoms? Would it be appropriate to tell middle school students...8th graders... that...

An atom has an equal amount of positive and negative charges. But those charges are not all in exactly the same spot. Electrons are closer to other atoms than the protons are. So, would a lone positive charge be attracted towards the electrons in an atom?

Hi there, Sorry if thisis a stupid question its just been bugging me for a while and I am not a scientist as such so need help with the answer... nuclear fission is where two atoms collide and release energy yes? nuclear fusion is where two atoms combine to release energy and a new isotope...

I'm stumped as to how many optic branches (modes) are present if there are X number of molecules in a unit cell and Y number of atoms in each molecule. I know that each individual atom has 3 degrees of freedom and more generally in a single unit cell, there are 3 acoustic branches (modes) and...

http://arxiv.org/pdf/1405.3492v1.pdf The birth of spacetime atoms as the passage of time The view that the passage of time is physical finds expression in the classical sequential growth models of Rideout and Sorkin in which a discrete spacetime grows by the partially ordered accretion of new...

hello, i am new in this forum , :) i want to ask if anyone know how to calculate the nuclear spin of an atom in general, i searched in google i didnt find any method of calculation :/ can anyone help me please, thanks

Homework Statement Here is a picture: http://puu.sh/bZtAu/82bdc201bc.png Homework Equations For force, F = (Ze^2)/4 * pi * e0 * R^3) * r f = sqrt(k/m) * 1/2pi Where e0 = vacuum permeability, 8.854 x 10^-12m and r = radius of hydrogen atom, 5.3 x 10^-11m The Attempt at a Solution I...

Homework Statement a) In the double slit interference pattern for helium atoms, the kinetic energy of a beam of atoms is 0.020 eV. What is the de Broglie wavelength of a helium atom with this kinetic energy? b) Also, estimate the de Broglie wavelength of the atoms from the fringe spacing...

Suppose I have a positively charged conductor with a cavity. There's a positive charge inside the cavity and the system has reached electrostatic equilibrium. Then there's negative charge surrounding the cavity and positive charge on the surface of my conductor. If I apply gauss law to the...

Nuclear fusion research focus on the fusion of hydrogen istopes and its potential forthe production of electric power. But is hydrogen the only element that can be artificiallly fused?? would it be possible to use a farnswrth or polywell fusor or any other type of usion reactor to fuse...

I am looking into some new physics and had the following question come up: You have a neutral gas of let's say, CO atoms at 1 nanoTorr. An electron(s) comes passing through the gas ionizing only 1% of the gas atoms. How long does it take for the gas to come back to neutrality? In other words...

Does electron excitation for atoms above hydrogen happen at the valence before the core electrons first? I know that for a gamma ray it is due to the excitation within the nucleus, but what about for normal emission spectra. Do we just shine a bunch of different energy onto the atom and...

I know that we aren't touching anything because atoms are repelling because electron can't touch each other. What I'm trying to figure out is texture. I think the reason we feel texture is because of the variance in atoms in a particular spot. For example a table is smooth because the...

I have seen only two arguments for the fact that composite particles, like protons, nuclei, or even Helium-4 atoms, are identical and can be considered bosons or fermions according to their total spin. The first, in Feyman's lectures [third volume, 4-2]. It is said that if the composite...

Just curious if we know what the placement of neutrons and protons are within an atom? Is one side heavier, can we determine this from polarity?

If a gas is bombarded with light will the atoms absorb the light and emit photons of an equal energy level?

I don't know much thing about rays. When I was studying Rutherford experiment, I saw that nucleus scattered the alpha rays with Coulomb forces, and naturally the opposite forces effect the nucleus. So do the nucles of atom moves to the direction of alpha rays' first direction?

Hello there. I did research on some of Schrodinger work. My question is the transfer of Energy between the Atoms and Molecule. Schrodinger made an analogy with the Cat/Atom Scenario but the real particle in question is the NH2 Mole & H-Atoms with ghost energy being observed. The reason I read...

I have seen similar posts, but I haven't seen what seems to be a clear and direct answer. Why do only a certain number of electrons occupy each shell? Why are the shells arranged in certain distances from the nucleus? Why don't electrons just collapse into the nucleus or fly away? It seems...

I was looking through a physics book that has the answers in the back. this is not homework. It asks about a neutral beam of hydrogen atoms going into a strong non-constant B field. It asks how many ways will the beam split. It says the answer is 2. Why is the answer not 3. spin 1, spin 0...

So if a Titanium Ion has a charge of +2, does that mean it has a whole charge of twice the electron charge...so 2Xe?

Why when phosphorus is added to silicon, phosphorus bind with only four silicon atoms and contributes with its extra electron, why doesn't just phosphorus bind with 5 silicon atoms since that is what it needs ?

Take the first orbital given to us by the time independent SWE, which is a sphere around the nucleus. Conventional teaching is that the electron is smeared across the whole surface area of that sphere. If the electron doesn't appear until after we measure it, how then do atoms repel each other...

Hey guys, I've recently read about the Tavis-Cummings and Dicke models and I got a little bit confused about them. They are suppoused to model N identical atoms interacting with a one-mode EM field, however the atomic operators are defined in the basis (for the case of two atoms)...

I am trying to figure out a method for using optical tweezers to manipulate individual atoms into new meta-material structures. I understand this would require a very complicated process. I thought of some general steps this process might use. This is roughly what I think it might require...

In Molecular orbital theory, when two atoms A & B come close to each other, their atomic orbitals (say their s orbitals) combine and make two molecular orbitals, one bonding and the other anti-bonding. How about molecular orbitals of three or more atoms? For three atoms say A & B & C we would...

One of the first things about QM we were taught in my undergraduate physics program is the deBroglie relation: λ = h/p Now, it makes sense that that this might hold for all elementary particles, especially since the evidence generally seems to suggest that the commonly observed forms of...

Homework Statement From a journal I read that the cobalt-based perovskite cathode usually has better ionic and electrical conduction but higher TEC compare to Maganite-based perovskite cathode. Because of the Co-O bond is weaker than Mn-O bond. e.g. Cobalt-based perovskite cathode...

New to this blogging, forum internet stuff so bare with me. Does anyone know if there is a similarity between the empty space separating the nucleus from the electron cloud of an atom, and the empty space found in the vast expanse of the inter galactic voids. The statement "Matter is composed...

We could have defined the supercell as a cube with side length 2a containing four atoms located at (0,0,0), (0,0,a), (0,a,0), and (a,0,0). Kindly explain how can a cell with side length 2a is possible with the following postions (0,0,0), (0,0,a), (0,a,0), and (a,0,0) ?

Hello,I have a question about 2 (or more) atoms coupled to an optical cavity. The equations of motion in the interaction picture for 2 atoms in resonnance with an optical cavity starting from 1 excited atom (C_{eg,0}(t_0) = 1 ) (g is the coupling constant) \begin{cases} \dot{C}_{eg,0} &= -...

would time dilation occur if for example, i was making a hydrogen atom spin with the center of spin the atom? would time dilation occur? because it didn't really traveled distance... or, if so spin a muon, would it decay faster if i was to spin it in an incredible amount of speed? but then if...

Dear All, I have read many posts on this forums about the interaction of photons with the atoms of transparent materials. The point that I was searching for in particular was "why is the speed of light in transparent material less than c". The explanations given by many about the absorption...

Hi. http://www.nt.ntnu.no/users/jensoa/E-FY1006-31mai2012.pdf Please open the link and go to page 11, problem 3. It appears, after all, I understand nothing when it comes to the wave function of Hydrogen like atoms. So I kindly ask you to answer some questions I got: 1) "A selection of these...

Recenty I learned that there is not real touch. That atoms never touch each other because of electons. I have two question to this. 1) Why we feel the pain(I think is because of brain analysys but I am not sure) 2) Why if I press hard my hand,I will mark that?? Why this sign in my hand will...

I had this question given in my class A spectral line from iron (mass 55.934 amu) atoms in the sun is measured as 637.4 nm. It's width is measured to be 0.053 nm. Calculate the temperature of the sun?Now I done this using a formulae I was given but it yielded an answer no where near 5778KAbove...

Hi! I've had this question for awhile. I asked my ochem professor and he didn't know how to answer it. My physics professor answered it but still left me with questions. In physics, the force of two charged particles is shows by Coulombs eq: F= k* q1 * q2/ r^2. My question is, why do...

Can an atom be considered as an example of a dipole? It has positive charge in the nucleus and negative charge around it?!

Can an atom be considered as an example of a dipole? It has positive charge in the nucleus and negative charge around it. So, can't it act as a dipole?

Homework Statement At transition from first excited state of rotator to ground state the molecule of HCl shoots out a photon with ##4,8\cdot 10^{-4}m##. How far apart are the atoms in the molecule? Homework Equations The Attempt at a Solution What is wrong with: ##\Delta...

Why does the "anomalous" Zeeman effect not show up on some atoms? I read this: I don't see why the electron spin affected the number of lines to go up in some atoms and not in others. The electron(s) on the H atom also have spin. Thank you.

Hi! Recently I have began to read up on my passion in physics in my spare time. I have encountered an experiment where lasers are used to decrease the speed of sodium atoms. The lasers are a wavelength that the sodium atoms absorb and then proceed to emit a photon. If the atoms are traveling...

Homework Statement What are the number of ionizable hydrogen atoms in phosphorus acid H3PO3? Homework Equations - The Attempt at a Solution I didn't even know what "ionizable " means. ( This is not a homework questions, I'm solving sample questions for an entrance exam) . So I searched the...

Why do atoms just have a general vicinity of which they rest in a solid?

If I have an atom with energy levels of -4 ev, -2 ev -1 ev and 0 ev and I radiate it with photons which cover a continuous range from 0 to 2 ev is it not possible for a 2 ev photon to move the electron from -4 to -2 and then a 1 ev photon to move it from -2 to -1 and then a 2 ev photon to free...

From what I understand chemical bonds arrive from the transitions of electrons between atoms and some atoms for a period of time don't have electrons. I don't understand, I thought electrons were tied to specific atoms. Any help would be greatly appreciated.

Why do atoms repel when they are close to each other and react when they are far from each other??

Hi. thanks for the pretty place. i want to ask: can atoms move from place to place without passing the space between them?

I was looking through my notes and came across this (above) I understand the calculation etc but I don't see where the number of atoms N was calculated? I don't see where it has come fromAny help would be great thanks in advanced

Hi! One can easily analyze the Hydrogen Atom since it is a two body problem. But how do you apply Quantum Theory to model atoms (such as iron) which are much larger and predict their behaviour in an environment? My guess is that you use statistical mechanics, but I only just started a...