What is Atomic: Definition and 852 Discussions

Hi friends, this is my third post of my curiosity. :woot: First of all a photonic vacuum (as defined by me) is a region of space where there doesn't exist any type of photons or EM radiations ( those too which are beyond the detection of our present tech... i.e. including each and every...

Helium has k-alpha of 24.5 eV whereas if we derive it using Moseley's law, then it is supposed to be 10.2 eV Also I then looked into many sources and found that Moseley's graph talks about elements having z>=10 only Later I found in few sources that the assumption that "one electron shields...

Excuse the simplified question title. I have very little knowledge in the world of organic chemistry, and chemistry alone. If I looked at the composition of banana (atomically), and then I got a little jar full of every element that is necessary to a banana's composition, could I make a...

Homework Statement A golf O-ring is used to form a gastight seal in a high-vacuum chamber. The ring is formed from a 100-mm length of 1.5-mm-diameter wire. Calculate the number of gold atoms in the O-ring. Homework Equations Volume of cylinder = PI*h*r^2 The Attempt at a Solution I got the...

Homework Statement With the atomic clock a second is defined as the time it takes for EM radiation to oscillate 9192631770 times, which equals the energy gap between two energy levels of a caesium-133 atom. Note: it's a translation and the term used with the oscillation is "oscillation periods"...

I am wondering how two orbitals of same n values can be orthogonal, for example how are a 2s and 3s orbital orthogonal? What I understand is a property of orthogonality is the product of the two wave functions integrate to zero over all space. I tried to look at this graphically and categorize...

Assuming a spaceship could be impervious to the damaging effects of a nearby atomic blast, what speed could the ship reach in space due to the explosion? Interested to know how to figure that.

Hi all! I would like to ask your help! I am a rookie in the subject. I have to admit i don't exactly interested in the mathematical way. I really don't have the "basic" advanced math which would needed it. :) Look at me if i would be a high school physics and chemistry teacher whose imaginary...

Homework Statement Silicon has the configuration [Mg] ##3p^2##. Explain why there are more L, S, J levels for the ##3p4p## configuration than in the ##3p^2## configuration. Homework EquationsThe Attempt at a Solution My thought is because in the ##3p^2## subshell you have less variations of...

A person said: "However uranium-235 (U235) makes up only 0.72% of normal uranium metal and has to be separated from the remainder (mostlyuranium-238) in special factories which makes uranium-235 (U-235) a little more expensive. An uranium-235 (U-235) atomic has three neutrons less than an...

This paper, http://arxiv.org/abs/1501.00996, proposes using atomic clocks for gravitational wave detection. It sounds similar to other ideas involving pulsar timing experiments. The twist here is utilizing satellites to provide a wide base for improved sensitivity. Sounds like an inexpensive...

Hello all, I was talking to a friend of mine earlier explaining why a force acts as if all the mass is concentrated at the center of mass. I know of no other proof than taking the time derivatives of the center of mass. Seeing as this was long before definitive proof of the atomic structure of...

And why the range of changing is different when we use different atoms as standards?

Is that because of some historical reasons or E=mc2(i mean something about binding energy)?

http://www.pluggakuten.se/wiki/images/3/3e/Prov221.JPG Solution

Hi! I saw something on my lecture notes that I don't really understand. It reads "Rare gases have filled s and p-sub-shells, which leads to a spherically symmetric charge distribution. Since electrons are indistinguishable they take on a common wavefunction. The point is that this results in a...

Hi, I am currently taking a course on Atomic and Molecular Physics, and the book for the course is https://www.amazon.com/dp/3642102972/?tag=pfamazon01-20. The course is based on this book. The Amazon link will allow one to preview the table of contents. The school library only has copies of...

I was trying to understand electronic excitation in Xenon. Most of the research journals are denoting different excitation levels in terms of Paschen notation, which i think, is generally used to represent excited states of inert gases. Can someone please explain how to use this paschen notation...

Two clocks in a spaceship floating though space at 99% the speed of light. One is a atomic clock and uses light and mirrors to measure time, the other clock uses cogs and gears like a conventional clock. From the perspective from inside the ship both clocks tick and tock at the usual rate...

I'm a chemist trying to understand atomic term symbol. If we list all the micro-states of certain multi-electron configuration, these micro-states can be grouped into several certain terms characterized by L and S. In other words, when we compute the ML and MS for each of the micro-state, they...

Hello! This is my first time posting, so please correct me if I have done anything incorrectly. There's something that I don't understand about the spin-orbit interaction. First of all I know that [\hat{S} \cdot \hat{L}, \hat{L_z}] \ne 0 [\hat{S} \cdot \hat{L}, \hat{S_z}] \ne 0 so this means...

Homework Statement Strong emission lines from calcium were observed at ##422.7nm##, ##610.3nm##, ##612.3nm##, ##616.3nm##, ##1034.9nm##, from transitions between ##4s^2##, ##4s5s## and ##4s4p##. The transition of ##422.7nm## was also observed at absorption. The singlet-triplet splitting of...

Homework Statement I need to calculate interference peaks using the atomic form factor for several lattice types for a lab report. I was given the expected answers but told I should also be able to calculate them.Expected results for rocksalt (eg NaCl): h+k+l = 2n fh+k+l = 4(fa+fb) h+k+l =...

How molar mass and atomic number are interrelated? Give me a detailed explanation. How to find molecular mass and molar mass for molecules?

Homework Statement I am trying to calculate the atomic form factor for various crystals (NaCl, LiF, GaP, Si) in an x-ray diffraction experiment. There seems to be very little information on this topic anywhere.Homework Equations [/B] I understand how to derive the geometric form factor Sk =...

Hi there, Sorry if thisis a stupid question its just been bugging me for a while and I am not a scientist as such so need help with the answer... nuclear fission is where two atoms collide and release energy yes? nuclear fusion is where two atoms combine to release energy and a new isotope...

Homework Statement This problem just has me find an atomic form factor for some arbitrary basis atom in a bravais lattice where the electron wave function is given (it has a dependence on the Bohr radius in an exponential). I calculated the form factor (a very long, nasty integral that...

Homework Statement :[/B] An atomic explosion can be approximated as the release of a large amount of energy ##E## from a point source. The explosion results in an expanding spherical fireball bounded by powerful shock wave. Let ##R## be the radius of the shock wave and assume that...

If one atomic mass unit is 1/12 of a C-12 atom, so 1 amu must be; 1 Amu = 1/2 ( Mass of proton + Mass of neutron + Mass of electron ) But the equation gives the answers that 1 amu is 1,6737 10^(-27) kg, which is different than the internet says I am using very sensitive values for the...

Okay can I first start of by saying sorry if there are any gramatical errors or mis-spellings I've got dyslexia and, well, sometimes things can get messy! So I have been really interested in Physics since I was really young, mainly in things like astrophysics and questioning why things happen...

Homework Statement Why does 25 atomic ppm oxygen mean 25 moles of oxygen in 1e6 mole Fe? Homework Equations # = mol*Avo The Attempt at a Solution I understand the ppm (parts per million) part. Hence why 25 ppm means 25:1e6. What I do not understand is how they go from atomic to...

Do electrons really exist as standing waves in an atom? If so, are these standing waves what are known as atomic orbitals?

Is there a theoretical basis for the spin of the nucleus of an arbitrary atom? I'm looking at this website: http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/nspin.html

When light passes in glass, water etc then velocity is reduced and direction changes HOW?

Would helium take less time to ionize than air, because it expand faster when heated up?

After specifying the primitive vectors of a structure namely (a,b,c) in Wien2k, one has to specify locations of atoms in unit cell.There are three components X,Y,Z which determine the atom location. I want to know whether "X,Y,Z components" are corresponding to vectors a,b,c or they are...

Homework Statement I was reading on Faraday's Cage and how if we are inside a conductor (car) we will not be harmed by the electric field strength of lightning if it strikes the car. (because conductors always have an E = 0 inside them because excess charge will always rapidly move to the...

My book here says that ' Despite the shielding of the outer electrons from the nucleus by the inner shell electrons, the attractive force experienced by the outer shell electrons increases with increase of nuclear charge. In other words, the energy of interaction between the nucleus and electron...

Hi guys! I have come across a problem I can't seem to wrap my head around. I've learned that E.M. radiation can be propagated by discrete packets of energy , photons. Is the energy of each photon discrete, or can it have a continuous range of energies depending on its frequency? I would be...

This has been bugging me for a year or so - sorry if this is off topic, but would anyone on the forum be able to name a book on atomic physics I read as a child? It was a non-fiction, illustrated picture book I read as in the late 70's or very early 80's, giving the history of atomic science...

although the distance from the nucleus and shielding effect [due to more angular volume] is more for 4s orbital than a 3d orbital ,but yet the energy for a 3d orbital is more than 4s orbital, why?

We measure time based off of atomic vibrations, so time dilation from gravity and velocity are nothing more than pressure applied to the atoms, slowing their vibrations. This isn't an accurate measure of what we consider time, but more of a measure of the reaction of atomic vibrations under...

Hello, well, I am totally new to this section of physics so my question may sound ridiculous, but here it is: When I was reading about the Bohr's atomic model, I learned about the Bohr and Rydberg equations (E=-2,18*10^18*Z^2/n^2 J and 1/λ=RZ^2(1/n1^2-1/n2^2) as well as their proofs. Then I...

What gives an atom its atomic spin?

I know this is a very common question but I've been seaching in forums all the time and couldn't find a clear answer. So quantum physics say that we can't actually "touch" anything because of our atoms( we're all made of atoms and they repel each other). correct me if I am wrong,please.. atoms...

This question was on Stackexchange, and no one was able to solve it. So now I'm posting it here, and I wish someone could help. I'm trying to derive the Bloch equations[1] from the Liouville equation[2]. This should be possible according to this paper[3], where it discusses higher order Bloch...

Homework Statement Three photons coming from excited atomic hydrogen sample are picked up. Their energies are 12.1 eV, 10.2 eV and 1.9 eV. These photons must come from? A)two or three atoms B)single atom C)three atoms D)two atoms The Attempt at a Solution By solving it i got single...

Hi there, I've just been having a little trouble with this short question from a past exam paper... Homework Statement "An atomic state has a dominant decay mode which produces an emission line of wavelength 6 \times 10^{-7} m and natural width 10^{-13} m . Estimate it's natural lifetime...

So in a lecture I'm reading up on we are given questions to answer during the lectures with no answers, and for this particular lecture the answer has been omitted and it is in none of our textbooks. But basically it says that a proton and a sigma plus, both have the same quark composition...

I'm an apprentice electrician taking night courses. My question isn't a specific mathematical problem. It's a query about a concept. Please let me know if there's a better way/place I can ask it. My text say that atoms can have a max of 32 electrons per shell, with 1-3 being ideal for...