Atoms Definition and 852 Threads

Wave functions that produce two lobes of electron probability on opposing sides of the core indicate that our point-like electron must tunnel through the nuclear core when the point charge moves to the opposing lobe. I don't understand what is the driving force for this process? Does this...

I recently had some thoughts about the big "space" between electrons and the nuclei and how weird it would be if that space were truly "empty". This led me to try to understand exactly what was empty space and the more I thought about it, the more I began to think about dark matter. I know empty...

Homework Statement An experiment is performed on a sample of atoms known to have a ground state of -5.0eV. The gas is illuminated with "white light" (400-700 nm). A spectrometer capable of analyzing radiation in this range is used to measure the radiation. The sample is observed to absorb...

Homework Statement (a) What is the minimum energy (in electron volts) that is required to remove the electron from the ground state of an ionized atom (Z=2)? (b) What is the ionization energy for this ion? Homework Equations After doing what I got the answer for part (b)... but I don't...

When considering a vibrating silicon atom. I'm just not sure how to do the conversion o.O

hello, I am curious about born repulsion of atoms, ie short range repulsion energy term proportional to 1/r^n. I find this in many solid state type books and they all call it the born repulsion and give no hints to its derivation or where it comes from. In _Atomic Physics_ 6th ed. by Max...

Can anyone explain electromerism to me? If possible do mention some links. I've tried Googling it but I couldn't find much.

I get the photo-electric effect but I am just wandering, is that the only principal on which lasers function? I mean do lasers "cut" materials by ionizing the atoms?

A few questions about atoms splitting and some about "cold fusion" Ok first I was thinking, when atoms fuse, they release energy, when an atom is split... it releases energy. Now, since energy is not created nor destroyed but only transferers, if you fuse an atom and then split it again, what...

I have seen some pictures of atoms taken by IBM, they seem like blurred round balls. Even other pictures with sophisticated instruments give a similar view. Are these pictures real ? Can they be trusted ? I ask this because electrons cannot be seen in any way aside from the fact that they are...

why silver atoms reflect light? why they don't refract it, like the Huygens's principle says?

Hi all, I am having a hard time understanding the following scenario (I'm quoting from page 305 of the "Electricity & Magnetism" textbook which you can access via Google Books): "Assume a simple model for an atom which consists of a point nucleus (+q) surrounded by a uniformly charged...

After ingestion of glucose, trace the path of the hydrogen atoms in glucose beginning within the digestive tract and ending with the oxidation of the glucose during aerobic respiration. Can anyone help me out with this problem? Thanks to everyone in advance!

what happens with the atoms, while there is reflection of light? What happens with the electrons or protons, are they reflecting the light and how?

I draw the formula without octet on sulfur and it says to draw it with octet on all atoms...I don't know what to do with the 2 electrons on sulfur or how to do it...thanks

I'm a little confused about something very simple. From a chemistry perspective I am told about how many electrons fit into each type of orbital. For instance, 1s and 2s can only have two each, the 2p orbitals total 6. It is composed of the Px, Py, and Pz and only two can be in each set, while...

Hi, I read this article on quantum entanglement of beryllium atoms: http://www.physorg.com/news80396930.html I have read other similar articles on the entanglement of photons and I understand that the spin of two photons can become entangled. My question is, when...

Using the first order perturbation theory I will determine the probability of finding some atoms in a certain state. The electric field is directed along the z-axis. But i don't understand how this is done. Should I convert the hydrogen atoms state equations into cartesian coordinates or...

"Artificial atoms" used to improve compact discs? This should be very entertaining for all of you. If you visit http://machinadynamica.com/ you will find many interesting devices. Some of them are complete bunk (for example, the "Clever Little Clock", the "Brilliant Pebbles", and the...

Homework Statement What is the RMS speed of Helium atoms when the temperature of the Helium gas is 247 K? (Possibly useful constants: the atomic mass of Helium is 4.00 AMU, the Atomic Mass Unit is: 1 AMU = 1.66×10-27 kg, Boltzmann's constant is: kB = 1.38×10-23 J/K.) What would be the RMS...

I know of the four fundamental forces ie the strong and weak nuclear forces, gravity and electromagnetism, but what is the force that holds atoms together in a substance and why is this force not considered a fundamental force?

Is there any evidence or even a theory that all Atoms are the same size? I was wondering what affect if the Big Bang or Bangs theory is correct, what difference if any would be found in the first atoms and the last atoms ever made? Was it a production line of atoms and would that mould not...

I'm new here and don't know anything about Quantum Physics but I love the concepts and ideas that surround the theories.well I know it sounds silly but is it possible? Its something I was thinking about when talking about Absolute Zero, they have used so many methods to slow the atom down so I...

I am a little bit confused. If U235 decays 2 neutrons, and the two daughter atoms posses a larger amount of binding energy per nucleon, then why is there excess energy? Why doesn't this process require the input of additional energy? I know I am missing something fairly simple.

The following link shows how to calculate the size of an atom, where can I find a chart where this has been done for all the elements in the periodic table? I know you can get charts of atomic radius but those are based on the distance between the nucleus of two bonded atoms and therefore the...

Ok so I just started taking this Bio 12 class after not being in High School for over 5 years! It is not what I thought it would be at all! Im kind of getting stuck on one topic and no matter who I talk to I still don't understand it. What is the dif between Atoms and Elements? I...

Calculate the number of moles of O atoms in 13.27 g Mn(NO3)2. Hi I did this question and it seemed pretty easy but there is this online assignment I am doing it for and it says I am not getting the right answer. Please can someone try it and see if they get what i do, or tell me what I am...

Hi. This isn't so much a homework question, but more of a conceptual understanding question. Lets say an atom has a ground energy level defined at 0J. The energy levels are: E1 = 0 J E2 = 7.77*10^-19 J E3 = 10.66*10^-19 J E4 = 14.1*10^-19 J E5 = 16.6*10^-19 J Now, if an electron...

I have a question about the electrons in atoms. This question is from quantum mechanics, but it is really a situation of classical electrodynamics. When the electron goes around the nucleus, it is said that the electron will emit electromagnetic wave and then fall to the nucleus. But in fact all...

Hi! This will be my first post :P Ever since I was a little kid I've wondered what exactly an atom is. Apparently these atoms have smaller particles like electrons, neutrons and protons which have mass (I am assuming its proven? If not I want proof!) and the nucleus of the atom is held together...

[FONT="Trebuchet MS"] Hi , I am rather new to this (well just found the site today) and I was wondering weather any of you knew the answers to my questions? I have searched the internet for any theories on the questions bit without and success, and I would like to hear your views. My first...

Homework Statement Quantum mechanics makes the electrons-in-the-nucleus theory untenable (for example on helium nucleus where before they know that a neutron exist, they thought that it was composed of four protons and 2 electrons). A confined electron is a standing wave, whose wavelength in...

Homework Statement Consider 10 He atoms as a system Thermodynamically, the state of maximum entropy hence the most likely macrostate for the system is 5 He to be excited and 5 in the ground state. But lower energies are more favourable so there should be more probability for the He to be in...

I was wondering about the process of atom excitement/ionization. If you have a atom that has 4 energy levels and a emitted photon from a laser that had the wave characteristics (F,L,E) as not the valance electron, but the sub shell below the valance electron (match the sub shell energy gap), can...

If I had a group of ten atoms in a vacuum what effect if any would raising the valance electrons per atom have on the other atoms? The second question is that when the conduction electron falls back to being a valance electron is all the energy given off as photons or is some heat (proportion?)...

Hello, I’ve looked over the other forums, and thought that this would be the best place for this. I’ve been thinking about this for a while and it has been very confusing. If atoms are the building block of matter, therefore everything is made up of atoms, how is it that atoms could...

If atoms are truly neutral(electrically) there should be no electrostic attraction between them, because there is no electric field out side the atom(All electric fields starting from the positive nucleus of the atom ends in the equal negative charge of electrons, which are inside the atom)...

From another forum an interesting question comes to mind: Suppose a universe made of only two hydrogen atoms {[P+]e-}. What would be the exact distance of separation where the total of all attractive and repulsive forces would balance ? Thus if < than this distance, union of the two atoms to...

One of my students Chris wanted to ask this question: are atoms perfect spheres? I could have offered one of my own answers to this but I think he would prefer to hear what you guys have to say. The only thing I would say is that I like the question because of its apparent simplicity. I...

Hi; I got a question related to Bohr's model but I'm not sure how to interpret the equations given what I know. Here's the question, sorry if it's a long read: The Bohr model correctly predicts the main energy levels not only for atomic hydrogen but also for other "one-electron" atoms where...

which has more potential energy, a Br2 molecule or two separate bromine atoms? I put the molecule because the fact that it is both attracted and repelled by the charges increases its potential energy. I just want to confirm if I'm right.

Why do atoms prefer filled, half filled, or empty shells?? What is the reason for this?? In chemistry, they tell you that atoms are "happier" in these states, but WHY? Nobody can seem to give me an answer. I have a hunch that it has to do with entropy of the various configurations, but can...

http://physicsweb.org/articles/news/10/10/6/1?rss=2.0 ===sample=== 5 October 2006 Danish physicists have managed to light-up a cloud of atoms using light teleported from a source half a metre away. Since Charles Bennett and his team first proposed quantum teleportation in 1993, science...

this is one of lab question but i don't even understand please help me the question is 1. consider spherical atoms of radius R arranged in a cube closest-packed lattice. if a small cube is constructed so that its corners are at the centers of the corner atoms, then one-eighth of each corner...

How many Cr atoms in 78.82 g potassium dichromate? Potassium dichromate is \textrm{K}_{2}\textrm{Cr}_{2}\textrm{O}_{7}. I said: The molecular mass of potassium dichromate is: 39.1*2+52*2+16*7=294.2 So, in 78.82 g potassium dichromate, there are 78.82/294.2= 0.2680 moles of potassium...

What is the difference between an atom and an ion? Ion has net electric charge. So it shows electric property. It acts like a small charged ball. What about an atom? Does it behave as a neutral object? Atom has equal number of protons and electrons bind together in the space. For this it is...

Are atoms, or their sub particles, just concentrations of energy which do not disperse? This energy pushes other like energies away and thus creates a solid feeling?

I need help could someone please help me with this problem? How many atoms are there in 3.90 moles of sulfur (S)?

I have been given a set of questions as a pre-course task for my physics AS level and i would be very grateful if somone could check my working and tell me if I'm on the right track. One of the questions is how many atoms (with a given diameter of 0.0000001mm) can you fit into a 1cm^3 space. To...

Where i live in the UK all the A-level students have just had their results. It has been said on the news that a new A* level will be added to the A levels to differentiate between the bright and the very bright and that an example of an A* question would be: 8 million uranium atoms in...