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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27
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4answers
3k views

Do electrons have some volume, area or shape?

I am in 8th grade now and when I was in 6th grade, my science book had diagrams of the electronic configuration of atoms. The electrons were round like spherical balls. Is it true that the electrons ...
11
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2answers
194 views

Terminology of atomic spectroscopy: Difference Among Term, States and Level

In A Primer on Quantum Numbers and Spectroscopic Notation Contents, the concept of a term and level is described as a) The level is the set of 2J+1 states with specific values of L, S, and J. ...
11
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1answer
220 views

Cause of uniform glow in cathode ray tubes

I got the following extract from a chemistry book (emphasis mine): It is observed that current does not flow through the gas at ordinary pressure even at high voltage of 5000 volts. When the ...
7
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2answers
374 views

How is the potential energy between two atoms measured?

In class, we learned about the interatomic potential graph. How does one actually measure the potential energy between two atoms experimentally to ensure the graph is correct? What device is used?
6
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1answer
277 views

How does de Broglie actually prove Bohr's postulates?

We know Bohr said that the angular momentum of an electron is an integral multiple of $nh/(2π).$ And in de Broglie's wave equation, he said the circumference of the path of the electron traveling as a ...
6
votes
2answers
452 views

Why is there an orbital angular momentum if the electron isn't properly revolving around the nucleus?

I'm a tenth grader who's just been introduced to this subject of atomic structure, so please help. I recently read that an electron doesn't have circular motion around a nucleus, its motion is kind ...
6
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1answer
183 views

Empirical Evidence and Assignment of Orbital Energies (Electron Filling)

I see a lot of questions on electron configurations from students at various levels here. Students mechanically remember how to fill orbitals and sorry to say many teachers do the same. Not a single ...
5
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1answer
194 views

What happens to the first ionization potential when a hydrogen-like atom captures a particle?

This is a textbook problem from Resonance DLPD Physical Chemistry, Page #83: The mass of a proton is $1836$ times the mass of an electron. If a subatomic particle of mass $207$ times the mass of an ...
5
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1answer
196 views

Why the term 'unified' in “unified mass unit”? [closed]

Why different unit symbols - amu, u and dalton are used for representing atomic mass? And what does the term 'unified' mean in "unified mass unit"? Thank you.
5
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1answer
160 views

Who came up with the box and arrow diagrams for electron configurations?

In general chemistry texts, the electron configurations are sometimes shown in boxes with up and down arrows to show the concept of paired spins. My impression for years was that Hund used such ...
4
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1answer
652 views

What is the exact definition of the radial distribution function?

I have been very confused by the radial distribution function which is often used in chemistry to predict the probability of finding an electron at a distance from the nucleus. From Atkins' Physical ...
4
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1answer
584 views

In Bohr's model what is angular momentum in the lowest orbital?

Angular momentum is given by: $n\frac{h}{2\pi}$ where $n=1,2,3...$ And angular momentum is also given by: $\sqrt{l(l+1)}\frac{h}{2\pi}$ By the first equation angular momentum should be $\frac{h}{2\...
4
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2answers
4k views

How do we find the angular, radial nodes and the quantum numbers when the radial probability distribution curve's equation is given?

I am having serious conceptual issues with the Schrödinger equations. Please note that I only have basic school level (11th grade) knowledge of these equations and we are expected to know very little ...
4
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1answer
215 views

Volume of orbitals

As I was learning about atomic structure, the lecturer made a seemingly dubious claim: The volume of a p orbital is one-third that of the s orbital. Thus, inter-electronic repulsions are ...
4
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2answers
99 views

Is there a finite number to the possible state of electron in an atom?

Okay, I know you may say, there are infinite numbers of possible state of an electron between its ground state and ionic state, since energy levels get continuous as electron gets farther away from ...
3
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3answers
104 views

Bohr's model of an atom

This question is not very mighty. But I'm having a problem wrapping my head around the Bohr's atomic structure. The textbook says electrons revolve around the nucleus in fixed energy shells, with each ...
3
votes
2answers
82 views

Atomic weight = expected weight?

The atomic weight of an element, is it accurate to say that another way to think of it is the expected value of that element's weight if we were to sample one at random from the environment? Are man-...
3
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2answers
528 views

For hydrogen like atom, find velocity from potential energy

PE of system is given by $$\mathrm{U(r) = \frac{-Ke²}{r^3}}$$ assume bohr model to be valid Find velocity For this I used $\mathrm{\frac{-PE}{2} =KE}$ and then used $$\frac{mv^2}{2} =\frac{Ke^2}{2r^3}...
3
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2answers
80 views

Restrictions on transitions in Spectroscopy

Just for the sake of an example, let's assume a transition from one energy state to a higher energy state in atomic absorption spectrum If the energy difference between the ground state and first ...
3
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1answer
170 views

Electronic configuration of the actinides

I was reading about actinides and I need some help in understanding this paragraph from Concise Inorganic Chemistry by JD Lee - The electronic structures of the actinides do not follow the simple ...
3
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0answers
42 views

Are Slater’s rule and lanthanide contraction contradictory?

According to most textbook and the Wikipedia page of lanthanide contraction, the phenomenon is due to poor shielding of nuclear charge by 4f electrons. However, the σ value of 4f electrons to 6s is 1....
3
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0answers
682 views

Don't understand 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 ...
2
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1answer
96 views

Difference between probability and probability density of finding a particle in space

What is the difference between probability and probability density of finding a particle in space? I am at basics of the wave function and this thing confused me. Probability = $[\psi(x, y,z)]^2(\...
2
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1answer
66 views

Do different oxidation states of the same element have the same emission spectrum?

I looked at the flames of copper (I) chloride and of copper (II) chloride through a spectroscope and they looked the same. The flame colour is the same too. But since they have different oxidation ...
2
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2answers
381 views

Why did J.J. Thomson observe protons in his cathode ray experiment?

In this MIT lecture, at 7:22, the professor says that when J.J. Thomson added a positively charged plate on one side of the cathode ray and a negatively charged plate on the other side, he observed a ...
2
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1answer
47 views

Identifying orbital given electron probability density plot

Being a high-school student, I only have a qualitative understanding of the wave mechanical model of atom. Below are my inferences regarding the plot shown in the above picture: The concerned ...
2
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1answer
59 views

What facts are being used in this atomic structure question?

I wish to understand how to solve this atomic structure question: For the ground state, the electron in the H-atom has an angular momentum = $\hslash$ , according to the simple Bohr model. ...
1
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1answer
71 views

What is the unit of the Rydberg Constant? [duplicate]

In the image, the Rydberg constant seems to have two units. How is that possible?
1
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1answer
284 views

Radial Probability Distribution Curve versus ψ² versus r curve for 1s orbitals

My question is basic, but I have already referred to a couple of books. This is an excerpt from Linus Pauling's book: the most probable distance of the electron from the nucleus, which is the ...
1
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1answer
246 views

Strong or weak force between protons and neutrons?

I had learned that what keeps the protons and neutrons bound is the strong force and the weak force has to do with radioactive decay. but today I read an article from Science Daily that contradicts ...
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3answers
192 views

Photoelectric effect (AP Chemistry question)

Which of the following postulates regarding the photoelectric effect is considered to be INCORRECT according to the quantum mechanical model we currently understand? (A) Increasing the intensity ...
1
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1answer
88 views

Molecular dynamics (Mac OSX user): what software can I use to plot RDFs for NPT simulations? VMD only works for NVT (constant volume)

I would be very grateful if someone could recommend a way to plot RDFs for NPT ensemble molecular dynamics simulation results. I use CP2K to run NVT simulations and usually use VMD to process ...
1
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1answer
63 views

Doubt in a question related to electronic transitions in Bohr's orbits

Question In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inner-orbit jumps of the electron for Bohr orbits in an atom of ...
1
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1answer
515 views

How does the screening effect work for orbital in the same shell?

Energy of an orbital in a single electron system depends solely on n, while energy of orbital in multi electron system depends on n and l, why is that? I understand that the screening effect is at ...
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0answers
38 views

How did Thomson calculate the momentum of electron when he didn't know the mass of electron?

"This was proven in 1903 by J. J. Thomson who calculated that the momentum of the electrons hitting the paddle wheel would only be sufficient to turn the wheel one revolution per minute." This is a ...
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0answers
47 views

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 ...
1
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0answers
32 views

How did Planck reach the conclusion that energy comes in packets based on black body curves? [closed]

I understand that if wavelength continues to decrease energy emitted by an atom would get to infinite, but how does the max wavelength at a particular temperature translate to discrete energy packets. ...
1
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0answers
64 views

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 ...
1
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0answers
29 views

Strongest overlap among s–s, p–p, s–p [duplicate]

So, I was wondering, when overlap of orbitals takes place, among s–s, s–p, p–p which type of overlapping is stronger? Because in s–s more volume is being used in overlap, but the electron density is ...
1
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1answer
54 views

Does one atom of an element show the properties of a bulk of that element? [duplicate]

For example, does one atom of gold have a golden color?
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0answers
35 views

Constructing two body Hamiltonian for Helium atom in hydrogen slater orbitals single particle basis [duplicate]

I am trying to construct a two body states to calculate the matrix elements of electronic Hamiltonian of Helium atom. $$H=-\frac{1}{2}\nabla^{2}_{1}-\frac{1}{2}\nabla^{2}_{2}-\frac{2}{\vec{r}_{1}}-\...
1
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0answers
844 views

Why are 4s electrons removed before 3d electrons? [duplicate]

According to Aufbau's Principle energy of 3d orbital is greater than 4s orbital, so which filling 4s if filled beforehand 3d. Whereas while removing electrons 4s electrons are removed first. Why? I ...
1
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0answers
169 views

Rutherford's alpha particle scattering experiment for sheets made of different metals [closed]

The correct order of increasing number of alpha particles passing undeflected through the foils of Au, Ag, Cu and Al of 1000 atoms thickness each in an alpha scattering experiment of Rutherford would ...
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0answers
47 views

Probabilities of Electrons in Orbitals [duplicate]

I've heard both of the following: An orbital is a region where there's a 90% probability of finding an electron An orbital is a region where an electron spends 90% of its time Are these essentially ...
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0answers
177 views

Quantum Mechanical Model of An Atom, Shells, Subshells [duplicate]

I've just been introduced to the quantum Mechanical Model of an Atom, so please bear with me on this one. Are Subshells and shell physical things, like do they really exist, or is it a concept only to ...
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0answers
47 views

How did the atomic number and atomic mass of elements discovered? [closed]

Elements are small for our naked eyes.so,how did the discovery of its atomic number and mass number took place?
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0answers
59 views

Why do objects gain electrons? [duplicate]

I have read that objects gain electrons to become negatively charged and also that they lose electrons to become positively charged. I have also read that same charges repel each other and non-same ...
0
votes
1answer
429 views

How are the molar mass and molecular mass of any compound numerically the same?

This observation is really annoying me, and the internet isn't providing me with any solid answers. Either their definitions of molar mass completely differ, or they don't stick to their own ...
0
votes
3answers
847 views

What are the possible magnetic quantum numbers of silver? [closed]

What are all the possible quantum numbers ml and ms of the electrons in the outermost s orbital of silver? I'm new to this concept. Can anyone walk me through this?
0
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1answer
112 views

Confusion about electron arrangement in elements

My textbook says, "The first shell can hold only 2 electrons. The second and subsequent shells can hold 8 electrons to give a stable noble gas arrangement." Can someone explain me if it is MAXIMUM 8 ...