Tag Info

New answers tagged

2

The expression you have there looks like that of the electron relative to the proton.


0

By removing all the spaces between nuclei you are converting the matter to degenerate matter, which is what happens at the centre of a neutron star. The density of matter at the centre of a neutron star is $6 - 8 \times 10^{17}$ kg/m$^3$. The density of a human body is around $10^3$ kg/m$^3$ (a bit less when you inhale and a bit more when you exhale) so your ...


2

First, note that the Bohr model of the atom has some shortcomings. Physicists have developed more accurate models since this one. But let's ignore them for this. From the wording of your question I believe you are curious about the nature of energy when the electron is in a uniform circular orbit. That is, no energy transitions. (In modern language, you are ...


0

(Not being able to comment is very annoying!) Why do you think 'This force of attraction gives energy to the electron' / what exactly do you mean by that? The fact that both particles are electrically charged sets up an electrostatic field, which in turn gives a term in the potential energy of each particle. In the Bohr model the energy of the electon is ...


0

The force between the electron and proton is electrostatic. The electron has a negative charge and the proton has a positive charge.


2

1) does "atomic density" correspond to "atoms in a volume unit that partecipate to the stimolated emission process"? "Atomic density" means number of total rubidium atoms per volume of gas, not just the ones that happened to participate in the absorption/emission process. 2) is $\sigma$ the cross section for a particular transition? (for example the ...


1

While DumpsterDoofus is right, perhaps this explanation might be helpful. A dipole is an asymmetric separation of charge, like this: $+ -$. A dipole can have many charges. The total charge must be 0. The center of charge for the $+$ charges and the center of charge for the $-$ charges must be at different places. A dipole can exert electrical forces on ...


0

So, why molecules with mirror symmetry have no permanent dipole moment? That's actually not true. For example, hydrogen cyanide has an infinite number of mirror planes of symmetry, but has a nonzero permanent dipole moment. Also, formaldehyde has two mirror planes of symmetry, and a permanent electrical dipole moment. However, for any molecule with ...


0

If a molecule has mirror symmetry then charge distribution will be uniform. Charge distribution on the left of the molecule will be equal to the charge distribution on the right effectively cancelling out, resulting in no permanent dipole moment. On the other hand if a molecule has no mirror symmetry then there will be a direction where charge distribution ...


0

Your statement $U=-kq^2/a_B$ makes the assumption that the total energy $E_\text{tot}=U+K$ is zero at the transition between bound and unbound. To find the ionization energy then, you want to find the energy input required to bring the total energy $E_\text{tot}$ up to zero. I say up to zero because for bound states the total energy is negative. To proceed, ...


-1

The electron cloud is not exacly centered at the proton in the hydrogen atom (or about the nucleus in other atoms). This is analogous to the Moon not exactly orbiting about the Earth, but the Earth and the Moon each orbiting about their barycenter (center of mass of the Earth - Moon System). In solving the Schrodinger equation for the hydrogen atom, it ...


0

Express V and E as explict functions of r. $$V = \frac{-q^2}{(4\pi\epsilon_0)r}$$ $$E = \frac{-q^2}{2(4\pi\epsilon_0)r}$$ Also, the previous page of Sah emphasizes that 2E = V.


5

Buckminsterfullerene (C-60) is about as close as you could get to spherical with 60 atoms. Earth's radius is 6,371,000 meters and Buckminsterfullerene's radius is 3.5 nanomoeters (nm). A carbon atom's radius is about 0.07nm (which I would approximate as the degree of deviation from roundness of Buckminsterfullerene). Therefore, Buckminsterfullerene ...



Top 50 recent answers are included