Atom Definition and 999 Threads

I was wondering why hot objects glow (such as a heated metal), what I found on wiki: "Thermal radiation is energy emitted by matter as electromagnetic waves due to the pool of thermal energy that all matter possesses that has a temperature above absolute zero. Thermal radiation propagates...

Homework Statement Definition of an unstable atom Homework Equations The definition = the answer. The Attempt at a Solution My guess is an atom with an unbalance in the strong or weak nuclear forces, leading to radioactive decay. Does anyone have any better ideas?

I had a thought-experiment I was pondering the other day. If you could somehow isolate a single atom inside a vacuum inside a Faraday cage, how would that atom behave in terms of translational movement?

Homework Statement The DE y''+\frac{2}{x}y'+ \left [ K+\frac{2}{x} - \frac{l(l+1)}{x^2} \right ]y=0, 0<x< + \infty. appears when working on the hydrogen atom. Find all the values of K (the eigenvalues) that generates solutions of the form \phi (x) such that \phi (x) remains finite when x...

I'm confused about something. If there are an infinite number of energy levels available to an atom, how and why would an ionization need to take place? The electron always has another energy level to occupy once its energy has been raised.

The Schrodinger wavefunction for the hydrogen atom scales as r^l for small r, where l is the orbital angular momentum. Is this changed in any dramatic way for the Dirac equation wavefuction? Does the small component of the Dirac spinor have the same small-r asymptotic behaviour as the large...

Homework Statement An electron in a H atom occupies the combined spin and position state: R21{(sqrt(1/3)Y10χ+) + (sqrt(2/3)Y11χ-)} If you measured both the z component of spin and the distance from the origin, what is the probability density for finding the particle with spin up and at...

Energy level of hydrogen atom -- with the electron replaced by a positron The energy level of a hydrogen atom is given by (without fine structure consideration) Eh = -13.6 eV / n^2 Suppose -- if the electron is replaced by a positron, what would happen to this energy level? The resulting...

Homework Statement As shown in class the electric potential energy of a water molecule is -5.33 eV. Which molecule is more electrically stable, H2O or CO? Why? Homework Equations EPE=Kc*q1*q2/r12 The Attempt at a Solution The water molecule's EPE is -5.33 eV. The carbon...

Homework Statement An electron in a hydrogen atom is described by the wavefunction: psi(r) is proportional to (psi(subscript 100)+2psi(subscript 210)-3psi(subscript 32 -1) -4psi(subscript411)) where psi(nlm(subscript l)) are the eigenfunctions of the hydrogen atom with n, l...

Hi, I just completed an assignment modelling an atom with one electron. The model was very simple, assuming that only coulombs law applied, then solving for standing wave solutions to the Schrodinger equation to find ionization energies. I was astounded how accurate it was. i thought it would...

Homework Statement what is produced when an alpha particle reacts with a beryllium atom Homework Equations The Attempt at a Solution i think that carbon 12 and a neutron is produced. please help me.

Homework Statement The neutral neptunium atom has 93 electrons. What is the magnitude of its electric field at a distance of 6.5x10-10 m from the nucleus? Hint: The number of protons in a nucleus is equal to the number of electrons in the neutral atom. q = 1.6e-19 * 93 = 1.48e-17...

what is the origin of a neutrino? from which part of the atom it comes?

What's wrong with my Q550 atom CPU?? I brought a Fujitsu Q550 one week ago from J&R via Amazon. I would like to use it with Onenote for jotting note during class However, it is running very slow, I would barely use the Onenote alone, can't open any other pdf ebook at the same time, otherwise...

hi, i have been reading this book about antimatter, "Antimatter" by Frank Close, and have a question. CAN ATOMS BE COMPRISED OF DIFFERENT FERMIONS OTHER THAN PROTONS, NEUTRONS, AND ELECTRONS? could they be comprised of those fermions if they have the same charges as protons, neutrons, and...

Homework Statement How many electrons, protons, and neutrons are there in an atom of 162Dy? If the gravitational force suddenly vanished, what would happen within the atom? If the electromagnetic force vanished what would happen? What would happen if the strong nuclear force disappeared...

Homework Statement The problem is attached Homework Equations T=E^2/4*(M+m)c^2 M=61amu, m=1amu E=710kev c=3*10^8m/s I conver amu to kg The Attempt at a Solution direct subtitution but the thing that I got the answer which is 2.21eV which is very small and it confused me have I...

If the electrons in an atom are negatively charged, and the nucleus is positively charged, what keeps them from coming together? I know that the old model of an atom as a tiny solar system is long obsolete, but still, there is supposed to be some discrete space between the electron structure...

If the atom is composed of a nucleus with positively charged subatomic particles, and the electrons are in the outer orbitals which are defined as in an electron cloud, why doe they not attract and the atom does not collapse on itself due to electrostatic forces of attraction. Also is there a...

Homework Statement 1)Determine the radius of the allowed orbits. Calculate the first orbit of Bohr's model for the hydrogen atom. 2)Show that the energy is quantized. Calculate the energy of an electron on the first orbit (fundamental state of hydrogen atom)Homework Equations L=n \hbar...

Explain how data from emissions spectra provide evidence for discreet energy levels within the atom?

Homework Statement 46-Ti 47-Ti Using the information in Table 1.1, calulate the relative atomic mass of this sample of titanium, Give your answer to 3 significant figures. Homework Equations The Attempt at a Solution I only know how to figure out the relative atom mass if...

I'm trying to plot the radial probability function for a hydrogen atom. I have the function itself (Psi2*4*pi*r2) my problem is that when I plot the function with angstroms on the x-axis, the y-values are larger than they should be (they look about right if I divide them by the bohr radius in...

Homework Statement The energy required to ionize a helium atom is 24.6 eV. If helium gas is bombarded with charged particles, at what incident energy will ionization of helium just be observed if the projectiles are (a) alpha particles (b) protons (c) electrons? Homework Equations Most...

Is space like a checker board where the pieces can only be in certain places like X X X X X X X X XoX...

here I am only considering the charge density of the nucleus, i.e the density of protons. I know that from mass density i have rho = m/v -> v = m / rho I'm not sure what mass to use here. Molecular weight? molar mass? where does avagadros number come into it? then is it simply charge...

How to prove there is no primitive cell of diamond structure with only one atom? Thanks in advance!

Homework Statement An atom which is in an excited state, can emit a photon with the wavelength of 330 nm at during the movement between two "energy niveaus". The last niveau has the energy -4.8 \cdot 10^{-19}J. What is the energy of the atom in the excited state? Homework Equations Not...

Can an electron (from outside the atom) collide with the nucleus of an atom, and does this happen at normal energy levels? What usually happens when it does? If it doesn't happen is it because the electrons of the atom repel the incoming electron with their charge. Finally same question, but...

elementary particles --their place in atom Homework Statement Do elementary particles reside inside the nucleus alone? Homework Equations The Attempt at a Solution

It's now years since I studied this, if anyone could help me remember. If I look at a hydrogen atom and it's shells. In the ground state there's 1s, the wave function is then: \Psi_{nlm}(r,\theta,\phi) = Y_{lm}(\theta,\phi)R_{nl}(r) = Y_{00}R_{10} Y_{00} = \frac{1}{\sqrt{4\pi}} R_{10}...

Hello, I am currently reading about electromagnetic fields: In one of the examples in the textbook we calculate the electric field of a hydrogen proton. We then compute the electric force acting on the orbiting electron to be 8.2 \times 10^{-8} N So I thought I could get the...

wen atoms can be re arranged at will, what wil the effect be on trade? wen u can make anything out of anything ths is a serious question, i think Newton was ridiculed an deleted off forums too. very rude! i cud be a genious!

Now, from what I understand, Bohr's model of the atom is outdated and flawed. But whenever I imagine energy levels, it is the Bohr's model that comes to mind. Do electrons really orbit around the nucleus? I would assume because of classical physics, even though the electron can be on any portion...

I hate to discourage anyone from doing science ("Stand Back!" indeed), but this goes a bit too far. While I admire his enthusiasm, if I lived next to this guy I'd be concerned.

http://hosted.ap.org/dynamic/stories/E/EU_SWEDEN_NUCLEAR?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2011-08-03-11-33-45 STOCKHOLM (AP) -- A Swedish man who was arrested after trying to split atoms in his kitchen said Wednesday he was only doing it as a hobby.

Is there any derivation of the bohr model for hydrogen using Ehrenfest theorem. References are appreciated.

I do not understand if you accelerate a hydrogen atom to 90% the speed of light its mass is greatly increased. Are the forces that hold it together increased? If not how is it different, will it fall apart? If the forces are increased in relationship to the mass of the atom the energy...

Homework Statement Use [H_{0},r_{j}]=\frac{i\hbar}{\mu}p_{j} for the Hydrogen atom (where the j's denote the jth components in Cartesian coordinates) to prove that <n_{f},l_{f},m_{l,f}|p_{j}|n_{i},l_{i},m_{l,i}>=-i\mu\omega<n_{f},l_{f},m_{l,f}|r_{j}|n_{i},l_{i},m_{l,i}> Homework...

as i know,bohr's discovery reveals that atom consist of central nucleus and electron orbit around them in empty spaces my question is-why aren't virtual particles being produced in those empty spaces?

Homework Statement So I've been racking my brain around the hydrogen mean values. \left\langle \frac{1}{r}\right\rangle=\frac{1}{a_0n^2}, that I can solve with the recurrence relation in Schaum: \left\langle r^k\right\rangle=\int_0^\infty r^{k+2}|R_{nl}(r)|^2dr by simply putting in...

Homework Statement part b) Calculate the recoil shift for the emission of the most energetic Lyman line from a free atom of hydrogen. 2. The attempt at a solution My question isn't a physics one per se, I'm stuck on terminology. What is meant by "the most energetic Lyman line"? I'm use...

Imagine that:- When a nucleus suddenly dissapears in an atom .What are the changes occurred around an atom .

For a summer class, I’ve been trying to get the quantum picture of an atom at least in conceptual terms, no math. I understand how, if you think about an atom like a one-dimensional box, an s orbital is like the first fundamental wave, and a p-orbital is like a sine wave, and I understand how...

Seems like a simple questions just got into a little bit of a debate, and need some clarification. Is the Atom and its particles proven?

Most common isotopes of He has 2 neutrons, Li has 3 neutrons and so on right, until Z increases to higher numbers and we get to elements like iron, where the nucleus doesn't have equal numbers of protons and neutrons anymore. But why isn't the number of protons and neutrons equal in the most...

I noticed many PF threads mention ground state of Hydrogen atom. At the same time it is two body problem considered to be solved by separation of variables. It is true, of course, that we can find basis wave functions (solutions of Shroedinger equation). But why does anybody think, that...

If a photon is not absorbed by an atom during collision, what determines the direction of the reflected photon? Explicitly... Does the photon reflect off of the valence probability 'shell' by abiding angle of incidence = angle of reflection? This seems counter-intuitive to me because some...

Homework Statement The mass of an atom can be determined by ionizing it and accelerating it through a known electric field followed by a known magnetic field. The ion’s circular path is then measured. Calculate the mass of a chlorine anion of charge 3.20 x 10^-19 C if it follows a circular...