A nucleus made of protons and neutrons surrounded by a cloud of electrons equal in number to the protons.

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116 views

How nuclear fission works in power plants? [closed]

As per the laws we are not able to see atoms (atom is microscopic). Then how does the nuclear fission works? *. In nuclear fission, splitting atoms is a exact calculation or probability(like we 1 ...
3
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1answer
136 views

If we cut an object in half and touch the two halves together, why do the bonds not reform automatically?

A friend recently posed this question to me: let us take an arbitrary object and cut it into two pieces (not necessarily equal in any way). If we touch the two pieces back together so the object ...
51
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1answer
7k views

Is it possible to “see” atoms?

As per my knowledge, atoms are small beyond our imaginations. But there is an image on Wikipedia that shows silicon atoms observed at the surface of silicon carbide crystals. The image: How can we ...
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4answers
734 views

Atom Theory vs Quantum Physics

This never really occurred to me until now, so maybe it does not categorize as a really important question, but, according to Quantum Mechanics, anything that is not observed exists as a probability ...
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1answer
387 views

Do electron shells exist within equipotential regions?

I had to read up on equipotential surfaces recently and I noticed the pattern of equipotential surfaces around a point charge. The idea came to me then that since no work is done in moving charges ...
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1answer
2k views

Electricity is the movement of electrons or ions?

Electricity is the movement of electrons from one atom to another or the movement of charged negative particles (ions)?
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2answers
2k views

Is Palladium an exception?

I have been taught in school that atoms cannot have more than 8 electrons in the outer shell. Palladium atom's electron configuration is 2,8,18,18. Why isn't it 2,8,18,17,1 like the case of Platinum ...
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0answers
31 views

What exactly is cutting with a knife will look like on the atomic scale? [duplicate]

Some times I like to view the world in the microscopic scale .ie. at this level all objects any thing will be collection of atoms which we normally don't view with our naked eye. At that scale I ...
4
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1answer
138 views

How can absorption spectra form if atoms can't remain in an excited state?

I have been tasked to write a research paper on stars. However, I know very little about physics in general. I am learning about how we can glean information about stars by analyzing the light that ...
3
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1answer
640 views

At what angle does a single atom “reflect” a single photon?

Does this question make sense in the quantum world? Imagining a single photon (wave packet?) interacting with a single atom (its electrons etc) how do we currently describe/define the emitted photon ...
82
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5answers
20k views

What does it mean for two objects to “touch”?

If you've ever been annoyingly poked by a geek, you might be familiar with the semi-nerdy obnoxious response of "I'm not actually touching you! The electrons in the atoms of my skin are just ...
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3answers
3k views

What is the quantum mechanical explanation of the octet rule?

What is the quantum mechanical explanation of the octet rule? In other words, what makes the octet rule be true from a quantum mechanical view? How we explain what makes some atoms don't follow the ...
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2answers
565 views

Why are atoms of the same element exactly the same?

Based on what we know about atomic structure all atoms have an electron density function which describes the uncertainty in the position of an electron. Thus theoretically 2 atoms of the same element ...
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1answer
264 views

Where does the energy within atoms come from?

Most kinds of energy I know about involve a finite measurement and are transferred. In other words, energy in the universe is finite and is not lost or gained but only transferred through space one ...
2
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1answer
1k views

In atoms, what is potential energy?

I was reading about how potential energy in atoms is measured by how far apart they are from one another. From what I have heard of potential energy, it's a way of showing how fast an object could ...
46
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5answers
7k views

What enables protons to give new properties to an atom every time one is added?

How does adding one more particle to the nucleus of an atom give that atom new properties? I can see how it changes it's mass, that's obvious... But how does it give that new atom different properties ...
3
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4answers
3k views

Is an electron/proton gun possible?

In the 1944 SF story “Off the Beam” by George O. Smith, an electron gun is constructed along the length of a spaceship. In order to avoid being constrained by a net charge imbalance, it is built to ...
3
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2answers
137 views

Why is Graphene So Strong?

There has been a lot of news about Graphene since its discovery in 2004. And as we are all told it is a revolutionary material which is very strong, conductive and transparent. But what is it about ...
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1answer
332 views

Why can't the electron enter the nucleus?

Actually, there exists an attractive force between an electron and the protons inside the nucleus, but the electron cannot be attracted towards the nucleus! What force balances that attractive force? ...
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2answers
1k views

Do we really not know why atoms 'decide' to produce a photon?

I was watching the Cosmos documentary where Neil deGrasse Tyson explained how certain energy photons get absorbed by an atom, which causes the electrons of that atom to climb into a higher energy ...
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0answers
53 views

What properties affect the color of item?

I already understand how gap bands work and how atoms can absorb/reflect light. I also already understand that rough objects will reflect light differently in comparison to smooth objects, but I do ...
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1answer
74 views

One color frequency items

I asked a slightly different question before, but how common are one color frequency items? Many things can reflect many colors of light, but predominantly show one under white light. If they are ...
3
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1answer
109 views

Why are some elemental materials grey?

How does grey occur in elemental materials such as metals? I believe that grey arises from the simultaneous reflection and absorption of all colors of the spectrum (in different atoms of course), as ...
0
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2answers
70 views

The Color White

How can something that is white reflect all colors? It would have to reflect all frequencies or at least blue green and red, correct? How can a two element compound, such as NaCl reflect all of these ...
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1answer
38 views

Reflections of objects of a particular color

How can any color reflect the color of light shone upon it? I tested this by shining different colors of light on different objects, and instead of becoming black, it reflected a hazier form of that ...
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4answers
4k views

What really cause light/photons to appear slower in media?

I know that if we solve the Maxwell equation, we will end up with the phase velocity of light being related to the permeability and the permittivity of the material. But this is not what I'm ...
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1answer
172 views

How can we prove that the shape of atom is spherical? [closed]

i am looking for a derivation that can prove that the shape of an atom is spherical . I experimentally proved this statement but i need a theoretical way.
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2answers
2k views

Why is Graphene Transparent?

Graphene is always in the news now a days and its key features are that it is; very strong, conductive and transparent. It is so transparent that each layer of graphene will only absorb 2% of Light ...
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1answer
92 views

photon absorption and emission

I was reading a book (Sears Zemansky) about this subject but I didn't understand something of an example, and this is that according to me there should be a process of emission for each of absorption ...
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2answers
155 views

Why are atoms empty so much?

To clarify: My question is not Why are atoms empty?, my question is Why are they empty so much? The classical orbit of an atom, roundly speaking, is where the probability to find an electron is ...
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1answer
118 views

How are atoms entangled, and can it be done remotely?

First of all, how exactly do you entangle two atoms? I've heard about how they entangled atoms in quantum Teleportation experiments, but I don't get how they did it. I've heard that the atoms must ...
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1answer
114 views

Angular momentum Bohr's model

I have been trying to derive speed, radius etc. in hydrogen atom using Bohr's postulates and not neglecting the coulombic attraction on proton. I know that they will be revolving around their centre ...
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1answer
39 views

Why Nitrides have internal polarization?

Why GaN has internal polarization? I know that in wurtzite crystal structure, the atomistic bonds are not equivalent and as a result there appears a net dipole and consequently a polarization. But ...
4
votes
1answer
594 views

What are independent parameters in Hellmann–Feynman theorem?

A typical example in textbooks about the application of Hellmann–Feynman theorem is calculating $\left\langle\frac{1}{r^2}\right\rangle$ in hydrogen-like atoms. Wikipedia has a nice demonstration of ...
0
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3answers
257 views

Do electrons get accelerated or decelerated by the atoms of the anode during X-rays production?

The electrons striking the anode get deflected by the heavy nucleus. Though the speed may or may not change, the direction of motion changes which leads to acceleration. The charged particles emit ...
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8answers
840 views

Can I throw a stone through my window without breaking the glass?

As far as I know, most of an atom is vacuum. Therefore, in theory, would it be possible for me to throw a tiny stone through my window without breaking it because no matter actually collides?
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1answer
173 views

Is charge transfer from A to B positive or negative?

I see this term pop up a lot -- for instance "charge is transferred from atom A to atom B", but it's never specified whether they're talking about positive or negative charge. I know electrical ...
0
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0answers
27 views

Photon absorption by a hydrogen atom : [duplicate]

How does the photon absorption takes place in a hydrogen? The classical mechanics shows the absorption of photonic energy resulting in the excitation of atom. Intuitively, a photon with frequency ...
1
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0answers
215 views

Total angular momentum in multielectron atoms

I have some confusion about orbitals in multielectron atoms. Let's say we consider an atom (Lithium, for example, $1s^2\, 2p^1$) and that the state of the last electron is [n=2, l=1, ml=0, s=1/2, ...
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5answers
6k views

Which experiments prove atomic theory?

Which experiments prove atomic theory? Sub-atomic theories: atoms have: nuclei; electrons; protons; and neutrons. That the number of electrons atoms have determines their relationship with other ...
34
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4answers
5k views

Are atoms unique?

Do atoms have any uniquely identifying characteristic besides their history? For example, if we had detailed information about a specific carbon atom from one of Planck's fingerprints, and could ...
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0answers
399 views

How to calculate the $g$ degeneracy factor for alkali metals and their singly ionized species?

The Saha ionization equation is $$\frac{n(X_{i+1})}{n(X_{i})} = \frac{(2\pi m k T)^{1.5}}{n_e h^3}\frac{2g_{i+1}}{g_{i}}e^{-\chi/kT}$$ where $\chi$ is the energy difference between the two ...
0
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3answers
164 views

The atom, solid or liquid? [closed]

Now I know what you may be thinking, "buddy, do you realize that the quality of solid or liquid is Made by the sum total of atoms in a thing therefore an atom can't be a solid or liquid??" This, good ...
20
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10answers
5k views

Where did Schrödinger solve the radiating problem of Bohr's model?

One of the problems with Bohr's theory to describe the hydrogen atom, was that the electron orbiting around the nucleus has an acceleration. Therefore it radiates and loses energy, until it would ...
8
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2answers
1k views

The distance between touching objects

What is the distance between, say, a cup of coffee and the table it rests on? What is the distance between two touching hands?
130
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3answers
16k views

How does a knife cut things at the atomic level?

As the title says. It is common sense that sharp things cut, but how do they work at the atomical level?
4
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1answer
154 views

How do mirrors look & behave atomically? [duplicate]

I was observing mirrors recently and I was thinking about how an mirror would look atomically. I was always used to looking at atoms as being colored that said, I was always concerned at how they ...
6
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3answers
23k views
3
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1answer
684 views

Why is cesium used to measure time in atomic clocks?

Seconds are measured by the frequency emission of cesium. Why is a frequency from the emission spectrum of cesium used as the standard in defining a second? Why particularly cesium?
7
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2answers
771 views

Miniature Neutron Stars?

Is the nucleus of a carbon atom, for example, as dense as a neutron star? I read that neuton stars also contain protons. Thinking more broadly, are we surrounded by quadrillion of quadrillions of ...