Questions tagged [atomic-structure]

For questions about the various atomic structure theories, including the Bohr theory. Not to be confused with the actual arrangement of atoms in macroscopic solids ([solid-state-chemistry]) or newer quantum concepts ([quantum-chemistry])

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What is d-orbital collapse?

When I was perusing the works of Schwarz on atomic structure, I came across the unfamiliar term of d-orbital collapse. He describes it as a variation in energetic sequence from group 1 to 3 elements ...
C. WJ's user avatar
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Did JJ Thomson know about Eugen Goldstein’s experiment discovering canal rays?

We learn that JJ Thomson discovered the electron in 1897. Several years EARLIER in 1886, Eugen Goldstein performs the same experiment but with the anode and cathode switched to produce positively ...
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Why Rutherford was shocked by results of gold foil experiment?

The way Rutherford's classic gold foil experiment has been presented (including by Rutherford himself) doesn't make sense to me. As many of you know, Rutherford famously described himself as being ...
theorist's user avatar
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Energy levels of carbon and selection rules

Here is an atomic physics problem I am trying to solve: The carbon ground state is $[He](2s)^2(2p)^2$. Suppose to excite an electron to the configuration $[He](2s)^2(2p)(3s)$. The spectroscopic terms ...
Andrea's user avatar
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Origin of the D1 line of sodium

According to the fine structure formula for exact energies (Sommerfield formula) $$E_{jn} = -m_\mathrm{e}c^2\left[1 - \left(1 + \left[\frac{\alpha}{n - j - \frac 1 2 + \sqrt{\left(j + \frac 1 2\right)^...
physicsstudent2's user avatar
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Why does titanium have lower affinity than scandium?

Electron affinity of atoms in the same row usually increases with the atomic number until the shell or half-shell gets full, and then it drops down. Some transition metals are exceptions from the rule,...
Pavlo. B.'s user avatar
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1 answer
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Why is strontium(II) ion bigger than krypton atom?

$\ce{Sr^2+}$ is exactly the same as $\ce{Kr}$, in terms of electrons and orbitals. The only difference between the two, is that $\ce{Sr^2+}$ has a couple of extra protons in the nucleus (and probably ...
peppa's user avatar
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Stark and Zeeman effects and their causes

In high school we are taught that Zeeman and Stark effect directly lead to the findings of further divisions of an electron's shell in an atom. What is exactly the reason that causes the spectral ...
Substitute_Y's user avatar
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222 views

What will the correct value of spin quantum number for last electron of Na+ ion?

Electronic configuration of $Na^+$ ion is $1s^2,2s^2,2p^6,3s^0$. I have noticed usually , we take spin quantum number as +1/2 first & then -1/2. So , like for the above Q:It is for first 3e=+1/2 &...
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How to calculate electric force on valence electron?

In order to understand the periodic trends more fully, I wanted to calculate the net force exerted on the electron (with the highest principal quantum number and azimuthal quantum number) of an atom. ...
Pranav Jain's user avatar
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What do brightness and intensity of spectral lines depend on?

My book states that it depends upon the number of photons of same frequency or wavelength absorbed or emitted. From what I understand, if many hydrogen atoms within the discharge tube emit at the ...
Happy Unicorn's user avatar
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Why is it impossible to determine number of visible emission spectrum of He+

We know that atoms emit spectral lines on excitation and de excitation. I was doing one high school question based on this theory Number of visible lines when an electron returns from 5th orbit upto ...
InfinityLies's user avatar
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Which ionic radius is most relevant for anticipating co-crystalization?

In the context of anticipating the likeliness that elemental impurities co-crystalize into the crystals containing an element of similar radius (see this question), which is the relevant radii to ...
Hans's user avatar
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Ambiguity on determining a relativistic Dirac orbital's "shape" when it has two angular components

Wikipedia says that a relativistic Dirac atomic orbital is a 4-component vector, with two angular parts and two spin parts. It also says, indirectly, that 'the top two components of a 2p(1/2) orbital ...
Kanghun Kim's user avatar
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Do degenerate states have exchange energy?

I have read that exchange energy exists between non-degenerate levels $1s$ and $2s$ or between $1s$ and $2p_x$ in the Helium atom in the first excited level: $$K_s = \left< 1s(1)2s(2)|H'|1s(2)2s(1) ...
Awe Kumar Jha's user avatar
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Calculating electrons emitted when quantum yield is given

In a problem, the wavelength $\lambda$ of a monochromatic light, power $P$ of the source, and work function $\phi$ of the metal on which the light is shown is given. Quantum yield is $n$. I have to ...
Ray Bradbury's user avatar
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molecular orbital theory and crystal field theory confusions

I am a high school student and I am very confused in Molecular orbital theory, it says that when two orbitals overlaps in the same phase, they form antibonding orbitals and when they overlap in ...
Arun Bhardwaj's user avatar
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Why are electrons filled in fourth shell before the third shell is filled?

I am a beginner and am learning about atomic structure and I am getting confusions regarding the aufbau principle. It is said that the electrons will be filled first in lowest available energy level. ...
Dheeraj Gujrathi's user avatar
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Do different eigenstates of total angular momentum have necessarily different energies?

Let $H$ be the Hamiltonian of a specific atom and $J$ the total angular momentum. Since $H$ and $J$ commute, they have common eigenstate. So we can label the atomic states by their energy and total ...
amilton moreira's user avatar
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Why is there a big jump in first ionisation energy between sodium and potassium?

I know the trend in group 1 is that ionisation energy decreases down the group due to an increase in atomic radius and more energy levels are added so more shielding, but I'm not sure why there's such ...
Katie's user avatar
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What will happen if electron as a wave undergo destructive interference while travelling in its Orbit?

Today I came across a justification of Bohr's angular momentum quantization using the De- Broglie's hypothesis. The justification said that since the electrons are having wave nature also then while ...
Tushar's user avatar
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How can the potential energy at the infinite energy level in an atom be zero?

I have recently learnt about atomic structure and the Bohr model of the atom and have observed a discrepancy between it and my previous knowledge based on physics. For simplicity, assume the atom is ...
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1 vote
1 answer
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Can you determine when the orbtials of an atom will hybridize?

We know that when it comes to C its orbitals hybridize (they become sp3 , sp2 or sp) and the energy levels of an hybridized orbital of this kind is lower than that of the p orbital that formed it but ...
David Sterlinsky's user avatar
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The existence of a principal quantum level or energy shell after the loss of an electron from the outer shell of an atom

With the loss of an electron from $\ce{Li}$ ($\mathrm{1s^2\ 2s^1}$), we get $\ce{Li+}$ ($\mathrm{1s^2}$), then the 2nd shell where the electron had been revolving in $\ce{Li}$ will get disappeared or ...
Shreya Murasing's user avatar
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1 answer
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Electronic configuration and symmetry labels of 3d$^7$ ions

In 3d$^7$ ions, e.g. Co$^{2+}$, the ground state is $^4$F, and it contains different levels due to the crystal field, such as $^4T_{1g}$, $^4T_{2g}$ and $^4A_{2g}$. Can anyone tell me what exactly ...
Chris Bohr's user avatar
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Can someone elaborate what it means when its said that electron shells do not exist in multi electron systems?

I'm an undergraduate student in chemistry. I'm trying to grapple with all the new stuff we're learning and making sense of it. Now I want to know if electron shells really "exist" in multi ...
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A question regarding hydrogen emission and absorption spectrum

I have read in many articles as well as my textbook that when an electric discharge is passed through a sample of hydrogen gas it excites the electrons and glows emitting light.When this light is ...
AJknight's user avatar
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86 views

How are the energies of, e.g. the 4p orbitals of the first transition series, determined?

Take a first row transition metal, say manganese. The 4s and 3d orbitals are occupied in Mn; each orbital's energy can can be definitely determined by ionising that orbital, obtaining the resulting Mn+...
Kanghun Kim's user avatar
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Why are HOMO and LUMO energies invariant under spin-flip?

Atomic theory says singlet and triplet energies for the same orbital differ because of exchange interaction. However, molecular orbital (MO) theory describes the energy between the HOMO (highest ...
siete's user avatar
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A better understanding of the screening effect and how it works?

What I am taught- Inner shell electrons shield the outermost electrons from the attraction of nucleus. More closer the inner shell is to the nucleus, more its shielding effect. thus $n_s > n_p > ...
user295079's user avatar
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0 answers
84 views

The necessary energy required to ionize 1g of potasium in its fundamental state if the ionization energy is given

The energy of ionization of the potassium is $\pu{6.94\cdot 10^{-19} J/atom}.$ Find the necessary energy to ionize $\pu{1 g}$ of potasium that is found on its fundamental state. Attempt. I really ...
Acyex's user avatar
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Comparing average radius of subshells for multielectron atoms

I recently came across a question comparing the average radius of subshells. A search on the internet gave the following result for single electron atoms: $$\langle r\rangle_{n,\,l}=\frac{a_0 n^2 \...
Govind's user avatar
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respective posistion of d and p orbitals in a multielectronic species

we write the electronic configuration of atoms as [noble gas core]4s2 3d10.that is that due to energy considerations(aufbau principle) in multielectronic species. what i want to know is whether the 4s ...
Karan's user avatar
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142 views

Why is atomic mass unit/unified atomic mass defined against Carbon 12?

I have searched the web all over this question and I have not really found an answer to my satisfaction. From my understanding of the topic so far, I understand that reason why concept of unified ...
TLo's user avatar
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Why does dissolved oxygen concentration decrease with increasing atomic number of metals?

I am looking at how metal ions ($\ce{Fe^2+}$, $\ce{Ni^2+}$, $\ce{Cu^2+}$, $\ce{Zn^2+}$, and $\ce{Ag+}$) affect the biochemical oxygen demand in water and used the Winkler's method to find out the ...
user105060's user avatar
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0 answers
53 views

Does it exist a transgression to Hund's rule of maximum multiplicity principle in this given electron box notation?

The following question arises from a set of statements from which I'm asked to state whether they are true or false. This is as follows: Indicate which of the following statements are true or ...
Chris Steinbeck Bell's user avatar
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137 views

Ratio of total energy to kinetic energy in hydrogen atom when the reference is changed

If in the hydrogen atom potential energy at $\infty$ is chosen to be $\pu{13.6 eV},$ then what is the ratio of total energy and kinetic energy (with the sign) for the first Bohr orbit? I think we don'...
Tony's user avatar
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-1 votes
1 answer
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Convergence limit of emission spectra for atoms with multiple electrons

In high school chemistry, students are taught that the convergence limit in the emission spectrum of an element can be used to determine the first ionization energy. However, what about the second, ...
Rafael's user avatar
  • 249
-2 votes
1 answer
76 views

Can't the wavelength of an electron increase or decrease to "fit" the wave perfectly in any radius?

I was reading about how de Broglie's electron-wave theory explained the quantisation of energy in a Bohr atom. What I understand is as follows: If the wave is to be arranged in the form of a circle ...
Arham Jain's user avatar
-3 votes
1 answer
40 views

Choosing energy levels for finding quantum numbers

When an element has multiple energy levels (i.e Titanium has $(Ar)3d^24s^2$), what energy level do we use to find the quantum numbers? Is it generally assumed the LAST energy level is used? or is it ...
Mathipulator's user avatar