Atomic Definition and 853 Threads

Also, why does red taper off slope towards the end of the subsequence, but green and purple never taper off in slope (flatten out)?

Hi PF Forum, How are you guys. I hope you guys are doing fine. I often come a statement like this. This earthquake is as strong as 1 million atomic bombs. This volcano is as strong as some million atomic bombs. And now in this video. Chicxulub impact "... this impact carried more than 10...

Someone wrote to me that the atomic bomb didn't exist and was probably a hoax. T They said that in World War II German scientists declared the bomb impossible. German scientists were the best in the world so the bomb must be fake.

Questions regarding Primitive Unit Cell (and what I think the answer are, correct me if I am wrong) 1. Can there be more than one Primitive Unit cells for the same crystal? yes, Wigner Seitz cell always will exist. There can be other primitive Unit cells along with Wigner Seitz too. But...

For part(b) The solution is, ##1:10##, however, is the wording correct? I don't see how to find the ratio of atomic mass, however, I can solve for the ratio of the molar mass. ##n_A = n_B## from part(a) by setting the internal energy equation for each ideal gas equal ##\frac{M_A}{m_A} =...

Let's say we have a point source of an EM wave in a vacuum of total energy E, and an absorber atom at some distance from this source, whose first excited state is at the energy B, with B < or = E. The energy of the wave is constant as a whole, but at each point around the source the energy...

Hello! I have some measurements of a given transition in an atom, where each event consist of the measurement of this transition and the associated uncertainty (as details, the way it is done, is for each event recorded we measure the laser frequency and Doppler shift it to the frame of the...

I find this very interesting. But it is above my head. Is there a simpler explanation/volume perhaps that I could get, consult? https://www.sciencedirect.com/topics/earth-and-planetary-sciences/atomic-energy-levels

I think Atomic physics gets into specific examples and experiments but I think I’m probably wrong. So, I have to ask, what is atomic physics and how is it different than quantum physics?

Hi everyone! I need some help in a specific task. It´s about this problem: An excited state of atomic calcium has the electron configuration 1s 2 2s 2 2p6 3s 2 3p6 3d1 4f 1 . (a) Derive all the term symbols (with the appropriate specifications of S, L, and J) for the electron configuration. (b)...

(I need help with the 2nd part as I can answer the theory part properly). For E=4 eV we can find the wavelength of emitted photon. E= 4 eV = 6.4087e-19 J Using E= hc/λ we get λ=310 nm (approx) My doubt is that this should fall in the Balmer Series but we know that the lowest wavelength value...

I did a prac where we tried to calculate the rydberg constant for hydrogen. We had a hydrogen lamp and we used a spectrometer that was hooked up to a photomultiplier tube to detect the wavelengths of light corresponding to the balmer series. In one section I need to write up a brief summary of...

What determines the time between atomic absorption and emission of photons? Is there a correlation to blackbody radiation?

In the past, scientists have experimented with atomic clocks aboard airplanes in order to prove the Special Theory of Relativity. In our humble opinion, ALL watches are accelerometers. Effect observed in a chaotic pendulum in free fall: Too bad they didn't do the same experiment with an...

I'm studying nuclear physics in a text, but at one point that is said: "Both the Coulomb potential that binds the atom and the resulting electronic charge distribution extends to infinity" , I don't understand what is that "resulting electronic charge distribution extends to infinity" what they...

Hi, I am 16 year old and I am very interested in Physics. This summer I solved Schrödinger equation using griffiths' introduction to quantum physics and other sources. I achieved to get an exact solution of the wave function but I would like to plot it in a programm in order to get the 3d...

What is the quantum spin of the valence electron in the silver atom in the furnace in the Stern-Gerlach experiment? . Up, down, at random, alternating, in a (quantum) superposition (of both), or none? Does it even have/get one until it's measured/observed /needed? . Does the second electron, in...

Here are two examples of chains. The end pairs of atoms are 8.0 angstroms and 9.2 angstroms apart respectively.

I have read that an electron requires certain minimum energy of threshold frequency to move an orbit However the energy needed decreases with increase in shell number The transition energy is reduced with each orbit For example The energy to shift an electron from 1st to 2nd orbit is much...

I don't understand, in balancing a nuclear equation, the sum of all the mass numbers and atomic numbers, given on the upper left and lower left side of the element symbol, respectively, must be equal for both sides of the equation. So why does the sum on the left side equal to 20, but the sum on...

Energy is equal to Planck’s constant times the number of waves in 1 sec. The time scale for electronic excitation is far shorter then one second. So when we talk about the excitation of an electron from a lower level to a higher level occurring at a certain energy, are we talking about the...

Hello! I read that if we have a 2 level system (say an atom) and we make it interact with a laser whose frequency is detuned from the resonant transition frequency of the system, the atom experiences an effective potential/force. In the classical description it makes sense, but quantum...

Hi! My name's Logan Knox and I'm aspiring to eventually understand the physics and nature of the quantum world in its totality, and I have a LONG way to go, but I have to get there by asking the right questions, and I think this is the first step to finding the right question to ask for this...

The International Bureau of Weights and Measures combines the readings of 450 atomic clocks around the world to obtain a time standard with sub-nanosecond accuracy. These clocks run at different rates - a clock at 1 km of altitude gains about 7 ns a day compared to one at sea level due to the...

I see this term comes up in KAERI table and elsewhere. Now let me guess here and tell me whether I'm correct. The only element whose atomic mass expressed in AMU is exactly a round number is C12, for all other elements it's either bit more or less so in order not to have to write long numbers in...

Hello! Can someone point me towards a place where I can find this book: I. B. Khriplovich, "Parity Non-conservation in atomic phenomena.". Ideally I would prefer a free version, but even paying (a reasonable price) for it is ok. Thank you.

Can someone explain me conceptually how one can use trapped ions to make atomic clocks? My basic understanding of trapped ions is, we can think of an ionized atom which is controlled by electric and magnetic fields. But i am wondering how can one build an atomic clock using trapped ions.

My question is the physics behind the LASER such as stimulated emission can be only explained by quantum mechanics only. We can represent LASER as coherent state in quantum mechanics only. Then how can we say LASER can be thought of a classical light source?

I had never heard of Schwinger's Quantum Mechanics: Symbolism of Atomic Measurements until very recently. I wonder what you people think about that QM textbook. Is it a good introduction to QM? A reference? Or, possibly an outdated and bad book? At first glance, it seems a masterpiece to me...

Atomic clocks. I tried to read wiki, read some QAs (on stackexchange), use web search. I would spend way much time to link all together alone, so I ask your help. I'm not sure if its called top-down or bottom-up. 1) Principle 1. Please confirm (or correct) my understanding of 1st underlining...

To measure the atomic hydrogen spectrum people often uses hydrogen gas tubes as light source. Since the gas in the tube is the molecule ##H_2## , why we obtain the spectrum of atomic hydrogen? My guess is that because the voltage is so high, so that the molecules are totally dissociated. If...

Hello I am trying to understand how to write the reduced mass into atomic mass units but i am confused how it was done. The equation is $$m_1m_2/(m_1+m_2)$$ For two similar masses in my particular case i have: $$m^2 / 2m = 1/2 * m$$ Then to convert to atomic mass units, the book says it...

So I've been hunting google for an answer but i cannot find a definitive one. If 0 Kelvin is the coldest temperature and it is where atoms cease to move does this mean that a photon in a vacuum is the hottest particle because it is in turn moving at the fastest speed possible? Second question...

Hey guys! Not a brain scratcher as such, just a clarification. When we talk about Bohr's postulates for his atomic model, would the Bohr-Bury scheme be involved in it? like in his postulates?

It is stated that the gram atomic mass of an element is its atomic mass represented in grams. The gram atomic mass of sodium is said to be 23g (isn't this number way to big to represent the mass of an atom?!) but if its the mass of one mole of sodium it makes sense(but won't that be molar mass)...

Hi, I found the two sections in red a little confusing. I'd appreciate it if you could help me with it. Source: https://en.wikipedia.org/wiki/Atomic_mass#History The existence of isotopes was first suggested around 1913[reference]. The first periodic table by Mendeleev in 1869 used...

When we touch something, will there always be a layer of air between us?

Oritals, other than s-orbitals, don't have spherical symmetry while the atomic Hamiltonian does have spherical symmetry. How is this possible?

I have searched in vain for a detailed calculation of the frequency 9192631770 Hz from basic physical constants using Quantum Mechanics. Can anyone help with this please

I was studying about atomic spectra of mono-electron species and in the pic it describes the ##4## series (principal, sharp, diffuse and fundamental). However I'm a little confused by the formula.Here my doubts are: Thanks for reading. [1]: [2]...

Hi, The following is an excerpt from Avogadro's biography. "Obviously, Avogadro could not accept the rule of simplicity adopted by Dalton. And thus he challenged the composition attributed by Dalton to ammonia, water, and the oxides of sulfur and phosphorus. As for the weights of ammonia and...

Quick question: let's say we have an atomic electron in the ground state which requires, say, one "unit" of energy* to jump up to the next orbital energy state. If a photon arrives with a bit more or less than this, say 1.00003 or 0.99997 units of energy, is there some finite, non-zero...

I've been looking hard (really, I have) for an explanation of what 'spin' is. Is there any way to explain this in a physical-real way, or is it 'just a thing'? Every description I have come across, and I mean dozens, say something like 'well, it's like angular momentum but it isn't really that...

Nitrogen has an atomic number of 7. Thus, A nitrogen atom has 7 electrons. Nitrogen’s electron configuration is: [He] 2s2 2p3 The nitrogen element has five valence electrons present in 2s and 2p orbitals. So it would have five dots placed around the symbol for nitrogen. Is this correct? I need...

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I recently looked at a transcript of a 1991 interview of Hans Bethe, where he recalled the suggestion that an atomic bomb could ignite the air. "Teller at Los Alamos put a very good calculator on this problem, [Emil] Konopinski, who was an expert on weak interactors, and Konopinski together...

Summary: The Space Between the Nucleus and Electron Shells? What composes the space between an atom's nucleus and its electron shells?

I know that direct interaction of opposite chirality(?) particles results in annihilation(eg. proton and antiproton). And I have read that proximity of quark and antiquark, even if in separate subatomic particles, results in at least partial annihilation(eg. Antineutron and proton). But I am...

Is atomic electron transition a phase transition? https://en.m.wikipedia.org/wiki/Atomic_electron_transition

Moderator's note: This is spin-off from https://www.physicsforums.com/threads/why-randomness-means-incomplete-understanding.975227 Reading this thread I would like to point out one aspect that makes me wonder personally and has also been mentioned here by other users. The decay of atoms...