Questions tagged [atoms]
A nucleus made of protons and neutrons surrounded by a cloud of electrons equal in number to the protons.
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The role of valence electrons in the electric field of atoms
I've read somewhere that hydrogen forms a strong electric field because it's a really small atom and it doesn't have any valence electrons.
My question would be, how does this conclude that it has a ...
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Confusion on Energies of absorbed and emitted photons
My physics teacher shouted this atleast 3 times yesterday, 'a photon can be absorbed only when it's energy is EXACTLY equal to the energy difference between the energy states'
So my understanding is, ...
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Where does this (hydrogen molecule energy) graph come from?
I was thinking about the good old question of 'Why do molecules have lower energy than the atoms?'
And in a video (around 6:15), this good old energy graph is shown, which is stated as the 'answer' to ...
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Energy level photon spectra for different atoms
I'm trying to determine the photon emission wavelength ranges for different atoms.
For hydrogen, it's super simple. We use the $$ E_n = -\frac{13.6}{n^2} $$
Then, if we want to see the wavelength of ...
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If all microstates are equally probable, why do we see Hydrogen with its electron always in the ground state?
I have learned in my Statistical Mechanics class that one of the fundamental assumptions of thermodynamics is that all microstates are equally probable. However, in the case of the Hydrogen atom, we ...
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How electron, proton and neutron have mass numbers
As far as I know, the mass number of an atom means the amount of protons and neutrons it has. For example, the mass number of Sodium (Na) is 23 since it has 11 protons and 12 neutrons. Then how ...
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Paradox between Heisenberg and ground state? [closed]
According to Heisenberg principle if the electron is near the nuclei it is more likely to have a greater momentum $p$. So the energy must be greater. But the electron loses energy and has in fact ...
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Experimental ways of studying the structure of atomic orbitals
As far as I understand, the notion of atomic orbital was introduced by Bohr in 1913 in terms of his semi-classical model of atom. Bohr assumed that each electron in the atom has a certain energy and ...
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Excitation energies of molecules
How are the excitation energies of molecules "formed"? Are they simply the sum of the excitation energies of their single atoms or do they also or instead provide further ones?
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What’s happening with ions while a capacitor is being charged by a battery?
An uncharged capacitor has an equal amount of positive and negative charges in both plates, meaning there are ions in both plates which altogether have a neutral charge.
When you connect an uncharged ...
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Can you control where the electron from an ionised atom goes?
I was just researching about how atoms can be ionised to remove the electron from an atom. Can you determine (or even control) where that electron goes (eg. conduct it with copper)? Thanks!
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Will removing an outermost electron from the outermost orbital of an atom change the orbital geometry?
Does $\text{He}^+$ and $\text{He}$ have different orbitals?
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Is really change in temperature inversely proportional to primary kinetic energy of ideal gas molecules?
I was trying to derive Charles law. While deriving I got two results and one of these was unexpected. Those are,
$$\Delta t \propto \Delta E_k$$
Where, $\Delta t$ is change in temperature and $\Delta ...
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Are the atomic orbital balloons representations of some mathematical surface equation?
The atomic orbitals are usually shown in shape of fuzzy clouds and sometimes straight-up rigid/hollow balloon shapes.
I understand that actually they are representing the probability of finding ...
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What is so significant about electron spins and can electrons spin any directions?
I just want to know what is so significant of with direction electron is spinning. Does it have any effect on the element or on the atom?
Also, does electron must spin up or down or can they also spin ...
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Is an electron in an hydrogen atom being measured by the nucleus?
In an hydrogen atom, the electron interacts with the nucleus by multiple forces, for example the Coulomb force. Does that mean that the nucleus makes quantum measurements of the electron?
EDIT: I ...
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How do atoms emit an electromagnetic wave (infrared radiation)?
From what I understand, when an object has a certain temperature, its atoms vibrate and this atomic vibration accelerates the electrically charged particles and this generates infrared radiation.
To ...
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Force required to remove an electron from an atom [closed]
For a certain experiment, it would be useful to me to calculate the force required to remove an electron from an atom of varying atomic number. As I understand it, calculating the energy required is ...
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Surface tension of a fluid
I understand that there is an imbalance of forces between molecules that lie on the surface of a fluid compared to those that lie within. This results in the surface area is minimised. However, I can'...
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In cathode ray experiment, will cathode run out of electrons after some time?
If we are performing an cathode ray experiment will there be a time when cathode stop sending electrons or run out of electrons, something like that.
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How does photons bounce back after being absorded by the atoms?
I just watched a video from the channel "Sixty Symbols" called "Why is glass transparent?".
Link: https://www.youtube.com/watch?v=Omr0JNyDBI0
The explanation about why some ...
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Physical meaning of the NV quantization axis [closed]
What is the physical meaning of the quantization axis (i.e. what is making this quantization axis exactly). I have yet to find resources that delve into it.
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Why do electrons orbit the nucleus instead of just sticking to it? [duplicate]
If the electron stays on the nucleus because of electrostatic charge, why do they spin around instead of just staying there?
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Would electrostatic charging break apart the configuration of hexagonal 2D nanosheet materials such as graphene?
Would electrostatically charging a 2D sheet of a material such as graphene, which is sp2 hybridized, wether by induction or conduction, break apart the sigma bonds between the Carbon atoms in the ...
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How do radiation particles escape the atom unaffected in radiation?
Alpha radiation is the emission of two protons and two neutrons from the nucleus of an atom (helium nucleus). Beta radiation is the emission of a high-speed electron from the nucleus of an atom as a ...
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Do subatomic particles in atoms change shape? [closed]
Do protons, neutrons and electrons change shape?
If they don't:
What shape are they individually? Are they irregularly shaped? Are they 'regularly shaped'? Spherical (like in textbooks, diagrams)? ...
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What perturbation can couple the helium metastable state $2 ^3 S_1$ state to the ground state?
It is known that this state is very long-lived, with a life time as long as about 8000 seconds.
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.103.053002
But still it is not infinite. Hence,...
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Degeneracy of the first excited state of Boron atom
I have a question while reading Charles Kittel's <Thermal physics>. In the very begining of Chapter 1, he gave an example of atomic energy level as shown in the figure below. Hydrogen is easy to ...
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Spin of electron and explanation of Zeeman effect
I am looking for a detailed exposition of the quantum computation of the Zeeman effect in spectra of atoms from which it would be clear that the spin 1/2 of electron is unavoidable.
As far as I ...
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Radioactive decay problem [closed]
Hey could someone please explain why the answer is C. I thought if the answer is C, the atomic number would be 44, not 50. I'm not sure I'm approaching this correctly. Thanks for any advice.
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Zeeman effect eq 1.38 in Foot Atomic Physics [closed]
I don't understand how to derive equation 1.38 in Foot's Atomic Physics (preview available on Google Books page 14 here).
I have included the relevant equations below:
First we have a differential ...
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On the expression for the hyperfine coupling constant
The hyperfine interaction can be written in the form:
$${\cal{H}}_{\rm{hf}} = {\mu}_I \cdot \vec{h}_{\rm{eff}}= g_{\rm{N}} \mu_{\rm{N}} \vec{I}\cdot{\vec{h}}_{\rm{eff}}$$
where $\mu_I:=g_{\rm{N}}\mu_{\...
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How to calculate the light emission spectrum of scintillator(CsI)?
I want to find some references on describing the physics of scintillation. As we know the lights generated by scintillator through atom activation and de-activation, and each material has a spectrum ...
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Does atomic particles have smell? [closed]
Do atomic particles like Sulphur or Hydrogen have their own distinct smell? Is the distinctive smell of Hydrogen Sulphide a combination of the smells of Hydrogen and Sulphur ? If not, then how do ...
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How is the center-of-mass motion separated from the relative motion in the nonrelativistic Hamiltonian for a Multi-Electron Atom?
The general nonrelativistic Hamiltonian for a single-electron atomic system with atomic charge Z that couples center-of-mass motion and internal motion is:
$$\hat{H}=-\frac{\hbar^2}{2m_{N}}\nabla^{2}_{...
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If phosphorus doesnt have a free electron then after doping silico, how is there a free electron that can move?
Phosphorus while bonding with silicon offers 5 electron so 4 of them bond leaving 1 extra electron, my question is how does that electron break out of its valence band? There should just be 1 extra ...
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Which order should I use?
I was working on hydrogen-deuterium mass ratio and I'm having a bit of confusion. When calculating the wavelength using this equation $$\frac{1}{\lambda}=R_H\left(\frac{1}{n_f^2}-\frac{1}{n_i^2}\right)...
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Which way do excited electrons prefer to go, directly onto ground state or through intermediate energy levels?
Do excited electrons prefer to go directly onto the ground state or to go through an intermediate energy level?
(I know it depends on the probability weather electrons take a direct way to the ground ...
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On degeneracies of energy levels in atoms
For hydrogenic atoms the energy levels are (in cgs units):
$$
E_n = -\frac{e^2Z^2}{2n^2a_0}
$$
This formula shows there's no dependence on quantum numbers $l$ and $m_l$. These so-called degeneracies ...
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Would superheavy muonic atoms be more stable than light muonic atoms such as muonic helium (hydrogen 4.1)?
Once we start dealing with nuclei the size of gold onwards the inner 1s orbital of an electron approaches relativistic speed. Now it's well known that muonic helium (hydrogen 4.1) has a mean life-time ...
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What is the energy difference between the 3d 4s valence subshells of iron (and copper)?
In gold, for example, the energy difference between the 5d 6s valence subshells is ≈ 2.7 eV (that's why it has color). But what about the 3d 4s subshells of iron and copper? What are their energy ...
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What happens after an atom releases a photon in laser cooling?
I am a high school student trying to understand how laser cooling works.
What I understand so far is that scientist take a bunch of atoms in vacuum and point lasers at them from all directions. The ...
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How exactly does Rutherford's gold foil experiment confirm that the mass of an atom is concentrated at the Centre of the atom?
I have been taught that the mass of an atom is concentrated of an atom, this can be proved by invoking the fact that very few particles are deflected. However, unless I'm mistaken the deflection is ...
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Why are atoms made up of only certain particles (protons, neutrons, electrons)? [closed]
Does it have to do with mass? I know particles like muons have the same charge as an electron, so why can't we have an atom that is made up of protons, neutrons, and muons?
Does the particle's mass ...
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If an atom has 'infinite energy levels', how does the photoelectric effect exist?
I don't quite get claims that an atom has 'infinite energy levels'. The photo-electric effect tells us that if photons of a certain threshold of energy are absorbed, the electrons will be freed from ...
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Amount of atoms in 1000kg of Deuterium per Britannica [closed]
I was recently attempting to calculate the amount of energy released in fusion reactions, and began using as a reference the Britannica article Energy released in fusion reactions. Within that ...
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De Broglie's justification for the quantisation of electorn orbit radius
I am reading about De Broglie and how his particle wave duality explained the fact that electrons can only exist in specific, quantised, energies/ranges from the nucleus, but I can't understand why. ...
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How can we be sure smashing atoms in an atom smasher does not cause harm? [closed]
I have a question about atom smashers in accelerators. How can scientists performing these experiments be sure that by smashing atoms they will not be producing the effect of a bomb, thus potentially ...
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Why does the closed-shell structure lead to high ionization potential?
Why does the closed-shell structure of atoms (those of the noble gases), lead to high ionization potential compared to the neighbouring atoms in the periodic table, on both sides of them, i.e. one ...
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Could there be a Planck sized black hole with positive charge in the center of each atom, moving so fast on its way that it has nearly any mass? [closed]
A few days ago, I asked if Planck-sized black holes at the centers of atoms might explain the positive charges in the Rutherford model of the atom.
Someone told me the Planck mass is much heavier than ...
