Atoms Definition and 880 Threads

Homework Statement The effective potential between two atoms of same mass m is: V(x)=-a\frac{1}{x}+b\frac{1}{x^2} where a,b>0 and x is the distance between them. (a) Calculate (order of magnitude) the distance between the two atoms in the molecule and its minimum possible energy. (b)...

Hi Everyone. I am confused about the science of colors. I will use an example in my question. I know that the color blue is caused by atoms reflecting blue wavelengths of light and absorbing other wavelengths of light. What I don't understand, however, is which part of the atom actually absorbs...

We often read that atoms are mostly empty space. A common example is given as, if the atom was a big as a football stadium the nucleus would be as big as a tennis ball on the center and nearest electrons circling around at far side of seats or something like that. How does this reconcile with...

Simpel question: does an atom consists of matter and charge? Yes/no?? If no Then what?

Is there a way to calculate how close two atoms can get before their electrons start to repel each other and prevent atoms from getting closer together. I'm guessing this is dependent on the size of the atom and it's number of protons and electrons. I am asking because I am working on a...

Hi everyone, I've been thinking about the quantum pencil, and I can't quite convince myself that you could perfectly balance a perfectly sharpened pencil even if the uncertainty principle went away. For those who are unfamiliar with the problem, you can read about it here...

I'm a high school student reading through a book on the discovery of the Higgs boson, and, among several other things, there's one part that I don't understand completely. I understand that the Higgs field is what gives mass to lots of particles that would otherwise be the same without the...

If an Atom doesn't decide if it will be a particle or a wave until it is measured, and we assume thought is the tool for measurement...In quantum physics would an idea be a particle or a wave or both?

Below is a paragraph taken from the web site, physicsclassroom.com: 'It is often useful to think of these electrons as being attached to the atoms by springs. The electrons and their attached springs have a tendency to vibrate at specific frequencies. Similar to a tuning fork or even a musical...

The question: Is there a gravitational attraction between two atoms if they are located at a distance of several light years of each other? Or physics does not have the answer to this question yet? ) (Sorry if this question has already been discussed on the forum. Please send a link to the topic...

(And fermionic atoms, as well). Knowing the weird statement that rubidium atoms and such are bosons and reading some of the threads, I've convinced myself that it is a perfectly acceptable possibility; however, I'm not so sure if I learned how to point my finger and say atom X is a...

To complete my Master's thesis, I am working on a problem that deals with an arrangement of initial atoms, and their positions are then changed according to a pseudo-random number generator with low discrepancy. My advisor told me that instead of computing the interactions between the atoms for...

Suppose we have an isolated H atom. We are looking its electronic transition. If we plot the intensity of the radiation vs frequency then what will be the nature of the curve and why??

Homework Statement Consider a evacuated long metal tube of length 'l' and diameter 'd' containing a metal source at one end. The metal source is connected to an oven and emits gaseous metal atoms in all possible directions. If an atom hits the walls of the tube, it will get stuck and will not...

Why are atoms taken to be spheres, and not of some other shape, in the calculation of the packing fraction of different crystal lattices? In other words, what experimental evidence and theoretical reasoning motivates this form of the atomic shape?

I have read that it is possible to go under recoil temperature limit using VSCPT (Velocity Selective Coherent Population Trapping) and that this method is based on atoms trapping in quantum state in which they can't absorb light. I have found same papers but they are too detailed for my...

Hi, I tried to calculate the distance resulting from Na iron atoms contained in 1 g. scaled in meters and by juxtaposing them in a single thread (segment). I did the following calculation with: Atomic radius : 140 E-10 meters Na : 6 E23 atoms in 56 g. of iron => ( 2 x 140 E-10 x 6 E23 )/56...

My understanding is the atomic model has electrons occupying shells and in particular numbers, but what's known about why they arrange themselves into shells and in those particular numbers? The teaching is that electrons have a negative charge and protons have a positive charge - but why do...

Dear PF Forum, I once read in several links just a couple of days ago, that the number of neutrinos exceeds the number of baryon in the universe by several orders of magnitude. 1. Is that true, that neutrinos are much more abundant than atoms? 2. Do neutrinos have mass? Not that they are...

Homework Statement There is an electronic transition between the first energy state and the ground state of a neon atom, emitting a wavelength of 746nm. The question asks for the energy of the transition and an estimate of the fraction of atoms in a sample that is thermally excited at 300K...

just picture what happens when you fill a 2 liter soda bottle with water (or any liquid) and try to pour it all out at once. it comes out in clumps. This means there will be competition, since all the water will try to escape all at once. the fact that there is competition means that there...

Hi Likely a stupid question. If atoms vibrate with heat, why don't hot objects make a sound, i.e transferring vibrations to the surround atoms (air) into our eardrums? They vibrate on ultra-infra sound? Or it's a extremely weak sound? or this is not the same vibration as the cause for sound? or...

I came across this today, but wasn't quite sure how it worked. http://www.sciencedaily.com/releases/2015/04/150409081436.htm Are the two atoms fired from opposite directions?

I read about scientists creating new heavy elements such 117 and that the properties of such exotic elements are mostly unknown because the scientist have just microseconds before they decay. Would it be at all possible to bond some new molecule with the heavy atom and some other appropriate...

From the ψ2 vs r graph (i.e probability of finding an electron vs distance from nucleus graph), there are no nodes for 1s orbital while there is a node in the 2s orbital graph.But they have similar structures right? Then why is there a difference in finding the probability of finding an...

Entanglement with negative Wigner function of almost 3,000 atoms heralded by one photon...

As the atoms of a material are brought closer together to form the crystal lattice structure, there is an interaction between atoms, which will result in the electrons of a particular shell of an atom having slightly different energy levels from electrons in the same orbit of an adjoining atom...

Hi friends, this is my third post of my curiosity. :woot: First of all a photonic vacuum (as defined by me) is a region of space where there doesn't exist any type of photons or EM radiations ( those too which are beyond the detection of our present tech... i.e. including each and every...

On the other hand, what if we only have two atoms of an element with a half life of ten years. Then after then years, only one atom of that original element remains. What happens next? Is the lone surviving atom immutable?

1) Do photons eventually run out of energy and stop producing light? 2) If atoms are non-solid and more than 99% empty space, what is the photon illuminating when it hits a surface? 3) What is the actual light being produced, as opposed to the photon producing it? 4) is it possible for a Higgs...

We are made up of atom & we are alive But a pen is also made up of atom but it is not alive

Between Cs and Na, the fermi energy in metal approximately doubles. why doesn't the carrier concentration also double?

For example, in glycolysis, NAD+ is reduced to NADH and then it's more energetic. Why adding electrons to an atom gives it more energy?

Homework Statement Two Ag atoms wits spin ##s=1/2## are at ##t=0## in state ##|\uparrow >|\uparrow >##. The first atom is in homogeneous magnetic field in ##y## direction while the second atom is in homogeneous magnetic field in ##z## direction. The strength of the two magnetic fields are the...

Hi there, I am reading an introduction for atomic physics. In one section, it introduces the energy levels for Rubidium and there are some labels like F=1, F=2 etc. shown next to the fine structure of a level . Also refer to...

The atmosphere consists of two toxic, and unfortunately abundant gases in our atmosphere. Carbon dioxide and methane. Carbon dioxide produced by factories are not needed in the atmosphere and cause harm. So is methane. Acegikmoqsuwy and I thought of an equation to solve this problem: CH4 + CO2...

Hello, Is it possible to build a qubit from an atom with a nuclear spin of zero (ie. 16O, 12C, 32S)? Would it depend on electron spin instead? Thanks!

I'd like to understand more about how/why carbon-based life comes about. All things are atomically based, why is it that carbon atoms/elements are able to sustain life better than any other element? Thank you

For those of you who have read the theorem, probably have also read Matt Leifer's review of it. In his review he says that the only way to remain psi epistemic is to be an anti realist(copenhagen), or to abandon the bell frame work. Is it viable to be psi epistemic but still believe that...

Atoms are all around us, right? we cannot move without interacting with atoms in the air the ground et cetera. This got me thinking about how infinite and vast space is compared to the seemingly small amount of planets, which are full of atoms. I use to think that planets were where all the...

I was wondering if the run away gravity in a super massive black hole could cause a lock up of sorts, and stop (nearly) all atomic movement? Packing the matter at it's core so tightly, that it would paralyze it at an atomic level. Could this possibly mean that near the center of these monsters...

This notion perplexes me. Could I please have this explain with an example(s). I am confused are atoms not made up of the same protons and neutrons which are just essentially negatively or positively charged particles which are made of quarks? Which as confusing as that can become. How can one...

In a bosonic atom i.e. Hydrogen, why do we never observe quantum tunneling past the coulomb barrier leading to multiple atoms occupying the same area of space thus (due to Newton's law of universal gravitation) accelerating towards each other resulting in nuclear fusion?

Can someone please explain the significance of resonance levels that forms when electron collides with atoms. How this resonance levels are different from other levels ?

Hi, last week I read Rabi's paper "The Molcular Beam Resonance Method". This paper contains the basic idea of the oscillation which we call "Rabi Oscillation" as many of you guys know. However, at the end of this paper, Rabi calculates nuclear magnetic moments of Li (atomic mass 6), Li (atomic...

Homework Statement Atoms of a certain material are in an excited state 1.8eV above the ground state and remains in that excited state for 2.0ms before to the ground state. Find 1) The frequency of the emitted photon 2) The wavelength of the emitted photon 3)The uncertainty in the energy of the...

A question about time dilation.. I find myself in an argument / discussion about the theory of time dilation, and it seems to me, that the terminology is really the problem. Would it not be more accurate to say that the effects of time slow, as speed increases ? To say that our test of clocks...

Hi everyone, For one of my PhD project I am trying to calculate the minimum energy required to displace a carbon atoms with gamma rays. Knowing the displacement energy (Ed) for C in diamond (30 -40 eV), I've managed to calculate the minimum energy required using electron with the formula...

Homework Statement (a) What is the minimum kinetic energy in electron volts that an electron must have to be able to ionize a hydrogen atom (that is, remove the electron from being bound to the proton)? Answer: 13.6 eV (b) If electrons of energy 12.8 eV are incident on a gas of hydrogen...

EDIT: "In what fashion are atoms or molecules added to a body, then attached, how exactly do they get replaced?" http://imgur.com/pmR8RB9 (I realize atoms are much smaller) Sorry for the crudity of my drawing but I think you get the general idea. I can't picture what happens? I believe they...