Atom Definition and 998 Threads

I think that it is correct to say that everywhere, spacetime is expanding. Is it expanding within the radius of electrons within atoms? Are the radii getting larger over time? I believe it correct that the distance from the nucleus to an electron exceeds the diameter of either one by...

Hi Please see the attached picture. It shows an atom, the filled black circle, which consists of a J=0 level (with m=0 sublevel) and J'=1 (with m' = +/- 1 sublevels). From the left is a nearly monochromatic laser impinging on the atom, which is linearly polarized along the same direction of...

so imagine a hyper-classical scenario. A single point elecrron is orbiting a point nucleus. No other charged objects are nearby. There is no em radiation from the electron. The electron orbits the nucleus in perfect circular motion. Zero orbital precession, zero uncertainty in the...

Homework Statement Lithium has an atomic number Z = 3. Two of its electrons have the quantum numbers {n, L, m{l}, m{s}} = {1,0,0,+1/2} and {1,0,0,-1/2}. Write down the corresponding set of quantum numbers for the third electron in the lowest energy state of the Li atom. Briefly explain the...

Do ions have a measurably different rate then their neutral counterpart or does the rate of radioactive decay and electrons have no correlation? Also, when a source states an elements half life is that the same for all of its isotopes?

The term (E-V) which stands for kinetic energy is used in Schrödinger equation.Kinetic energy of electron needs motion and fixed path which leads to the conclusion that electron is moving around the proton in orbits and is not spread out because derivation of Schrödinger equation is based on...

Homework Statement "If an alpha particle is fired straight at the nucleus of an uranium atom (q = 92e), at a velocity of 5 x 10^5 m/s, how close will it get to the uranium nucleus? Homework Equations Ek = (mv^2)/2 Ee = (kq1q2)/d The Attempt at a Solution Since the alpha particle and...

Does it give a lot or is nuclear fission only powerful when you have a large quantity?

if delocalization of electron in hydrogen atom means that it is spread out upto infinity it means that infinite time is required for the electron to be localized when hydrogen atom is ionized.Is it so?

do you consider Covalent radius, Van der Waals radius or atomic radius?

in a chunk of a pure element like iron-would the outside diameter of the the last electron shell ever naturally change from picosecond to picosecond?

Can an atom "give away" or "steal from another" an electron AND become an ion just to "satisfy" the Octet rule? Does an atom "prefer" to have 8 electrons in the outer shell MORE then it "wants" a neutral charge(not be an ion)? I imagine this varies from element to element. The elements i am...

we know electron revolves around nucleus at nearly (1/100)th of light speed..does this mean electron as very high relativistic mass such that It can become local source of gravity..but this is not the case..why is this so.?

Homework Statement Find the constant A such that the equation \psi(r,\theta,\varphi)=\sqrt{6\pi}A\sqrt{r}e^{-r/a} Wich describes one electron in a hydrogenatom, is normalized The Attempt at a Solution I figured this equation is seperable in the form...

I'm here got a small question, what is the different between L2 and L for the hydrogen atom. Do L2 means total angular momentum and L means angular momentum?:confused: Given that L2=l(l+1)ℏ2 and L=(√l(l+1))ℏ THX :smile:

I just did exercise 1.22 in Modern Quantum Chemistry by Szabo and Ostlund. This is a practice problem about linear variational method. ---------------------------------------------------------------------------------------- Question: The Schrödinger equation(in atomic units) for a hydrogen atom...

So the term symbol for the nitrogen atom is 4S3/2 This means L=0, S=3/2, hence J=3/2. My question is that if S=3/2 than this is a quartet, meaning there are four levels, yet I only ever see one state listed on energy diagrams? What gives? Obviously, I'm still trying to learn term symbols Are...

how does this change with introduction of another charge in its vicinity suddenly..and how does this vary as both charges repel each other after introduction of like charge.. btw I even wonder whether a electron which is outside a atom is in form of wave or particle..hope my questions are...

Homework Statement Consider a single ideal gas atom bouncing between two opposite faces of a cubic container, with sides of length l. Using m for the mass of the gas atom and Vx (V sub x) for the velocity component, give an expression for the number of collisions per second the atom makes...

The Schrödinger equation solved for the hydrogen atom gave good agreement with spectral lines, except for line doublets. To account for these electron spin theory was grafted onto the theory, despite the problem of electron being a point particle. In 1928 Dirac gives his different answer...

To work out the answer to this question, do I just find the total Mr of the products and divide it by the total Mr of the reactants (and then multiply by 100, and pick the biggest percentage?) Cheers

What is the uncertainty speed of a hydrogen atom inside a virus? Even though the vaue of uncertainty in position is not given. Any help on this would be greatly appreciated. Thanks!

Homework Statement An electron is held fixed at a distance of 1 m from the nucleus of a uranium atom (Z = 92). If the electron is then released, what is the magnitude of its initial acceleration? Homework Equations I am not sure which kinematic equation that I should use...

Homework Statement By expanding a MacLaurin Series show that E_{n}=\epsilon_{n} - \mu c^{2} = - \frac{w_{0}Z^{2}}{n^{2}}[1+\frac{\alpha^{2} Z^{2}}{n}(\frac{1}{k}-\frac{3}{4n})] Homework Equations Through a lengthy derivation I arrived at \epsilon_{n}=\frac{\mu...

Now let's say you have a mercury atom that has an atomic number of 80 , now let's say you take out a proton put of the nucleus by using a a lot of energy(nuclear binding energy). Now won't taking the proton out , turn it into a gold atom since gold has an atomic number of 79. ?

Homework Statement Neon is a monatomic gas; Density = 0.900 kg.m-3 Pressure = 1 atm Temperature = 273K. Density of liquid neon = 1207 kg.m-3 (i) Calculate the volume occupied by one gram mole of neon at a temperature of 273 K and a pressure of 1 atm. (ii) Determine the atomic...

Homework Statement The problem (4.13 (b) in Grifitths) asks to find <x^2> of the ground state of hydrogen atom. It asks to do so without new integration. Supposedly, there is some kind of symmetry and one can use the results from part (a) of the problem. Part (a) is finding <r> and <r^2> for...

how does look resistance when coming from atom to atom? I mean what is making that resistance, something with space between them or atomic forces?

Homework Statement A helium atom has a rest mass of He = 4.002603u. When disassembled into its constituent particles (2 protons, 2 neutrons, 2 electrons), the well-separated individual particles have the following masses: p = 1.007276u, n= 1.008665u, e = 0.000549u. How much work is required...

Hi, How do we calculate the temperature required to ionize an atom, say, helium. Also how can we find the number of atoms ionized or unionized at a given temperature? Boltzmann

Homework Statement how many possible quantum states for a nitrogen atom with electronic configuration of 1s22s22p3 Homework Equations ? The Attempt at a Solution So, the answer for this question is 20, but I can't for the life of me find out how. The book we're given is...

Homework Statement Given the following recursion formula: b_{j} = 2 \frac{kj - a}{j(j+1)-l(l+1)} \cdot b_{j-1} (where a, k and l are constants) how can b_{j = l} \neq 0 if b_{j - 1} = 0. Homework Equations The Attempt at a Solution This is a part question and I really can't see why. if...

Good morning. I am wondering what is the most accurate way to visualise an atom. In class the teacher draws spheres orbiting spheres, but, according to quantum mechanics, that is far from the truth. How do physicists visualise atoms or particles? Thank you.

Hello, why do the electrons with higher quantic number N have more energy than the electrons with lower N if they need less energy to be removed from the atom? Thank you!

Is spin of electron taken into account when people accelerate electron in LHC?

Suppose you theoretically have two betatrons each accelerating a particle near light speed in opposite directions. Suppose you collide both of these electrons together head on both at close to light speed. Since the collision is happening at speeds over the speed of light, does anything peculiar...

How do you strip a neutron from a particle? Thanks

Hello guys, I need the quantum mechanical description of the Cesium atom/gas with its hyperfine states, and preferably with some density matrix. I don't really know where to start my search. I googled a lot, and looked for articles and books, but failed. Any help is highly appreciated...

Hi all How does one calculate the recoil velocity of a hydrogen atom when the electron in it jumps from a higher orbit to a lower orbit (say from 3rd to 1st) ?

Does a ground state of atom actually exist on our planet or every atom or molecule is just somehow excited because of all the energy flying around?

Homework Statement In an examination of a certain element using the Debye-Scherrer technique the following diffraction angles (in degrees) were noted: 45.26/65.92/83.56/100.6/118.68/140.88 Radiation λ=0.1540 nm was used. Obtain two estimates of the atomic diameter of the element in...

Homework Statement By substituting the wave function \psi (x) = Ax{e^{ - bx}} into the Schoedinger equation for a 1-D atom, show that a solution can be obtained for b = 1/{a_0}, where {a_0} is the Bohr radius. Homework Equations - \frac{{{\hbar ^2}}}{{2m}}\frac{{{d^2}\psi...

Homework Statement Given the numerical value of a0= 5.3X10^11m in the Bohr hydrogen atom, find the radius of the first five orbitals as well as the radius for n=100. Homework Equations Rn=a0 x n^2 The Attempt at a Solution Could it be as simple as typing in for the third orbital...

Dear, I am reading a paper on Bose Einstein condensate and an atom laser. I have two questions which are bothering me for a time. - When you are going to make do all the atoms start with the same the Broglie wavelenghts or do they start with different wavelenghts due to different...

the electrical activity of an atom is the same electricity of a light bulb?

Homework Statement Using Hund's rule, find the fundamental term of an atom whose last incomplete subshell contains 3 electrons d. Do the same with 4 electrons p. Homework Equations The 3 Hund's rules. The Attempt at a Solution By fundamental term I'm guessing they mean the...

Homework Statement a group of atoms are confined in a point like volume in a laser based atom trap, the laser light causes each atom to emit 1.0 x 10^6 photons of wavelength 780 nm every second. the sensor has area of 1 cubic centimeter and measure the light intensity emanating from the trap...

Is it possible to replace one of the electrons in a heavy atom like uranium with an Antiproton and form a stable atom?

how spinor vector envolves in describing the atom

Assume the universe consists of a single photon, a single atom of hydrogen and a spherical detector (like an encompassing shell) with a semi-infinite radius. The photon gets "absorbed" by the hydrogen atom. Moments after the photon is emitted. My question is the following: from the time...