Atoms Definition and 880 Threads

What is the most accurate,closest and best photo that exists of an individual atom or molecule? There is the scanning tunneling microscope which is way better than the electron microscope,yet it doesn't photographs them by reflecting light off them,it uses quantum tunneling of electrons.I would...

Homework Statement You will recall from our discussion of the Franck-Hertz experiment that the energy difference between the first excited state of mercury and the ground state is 4.86 eV. If a sample of mercury vaporized in a flame contains 1.06×1020 atoms in thermal equilibrium at 1563 K...

Why is a single layer of atoms referred to as "2d"? I commonly hear a single layer of atoms referred to as being a "2-dimensional structure", when it so clearly is not 2-dimensional. Why do people make that obvious mistake? The same exact folks will also tell you that spacetime is a...

Here is one problem I have, I think it is simple, but then again I thought that every problem I had was like that only to discover that there was some trick in the middle, so please help. Caesium has exit work Wut = 1.9 eV. This means, therefore, that there are electrons in the cesium such...

It is a fact that atoms make up all matter. Is it possible for living organisms (plants, animals, insects, baterica, etc) to make more atoms by the processes of reproduction? Would it also be possible for atoms to be created as an organism grows?

The problem: Find the relative numbers of hydrogen atoms in the chromosphere (T=5000 K) in the n=1, 2, 3, and 4 energy levels. Solution: The Boltzmann distribution of energies is n(ε)dε=\frac{2πN}{(πkT)^{3/2}}\sqrt{ε}e^{-ε/kT}dε So using this I calculated the ratio to be, 1 : 5.4 x 10^-11...

a. Find the deBroglie wavelength of an electron traveling at 2*10^6 m/sec. b. Does this length come close to any familiar dimensions? Explain For part a. I did lambda=h/(mv) =(6.626*10^-34 J sec)/(9.11*10^-31 kg*2*10^6 m/sec) = 3.64*10^-10 meters I have the first one but I did not...

Homework Statement The magnetic field in a Stern-Gerlach experiment varies along the vertical direction so that the magnetic field increases by 26.00 T each centimeter. The horizontal length of the magnet is 7.1 cm, and the speed of the silver atoms is 922 m/s. The mass of the silver atom is...

Is dark matter dark because we hav never measured it directly on Earth with the atom? John

Hello. In Molecular Dynamics simulations, the Newton's equation of motion is used to calculate the time evolution of system. Once, I read in an introductory text that when the thermal de Broglie wavelength $$\Lambda=\frac{h}{\sqrt{2\pi mkT}}$$ is much smaller than the interparticle distance...

I'm curious, when an electron is bombarded by another electron or photon does the electron even jump at all if the incoming particle does not have the minimum energy to make it jump to the second orbital. That is do the electrons have some sort of knowledge before the collision occurs and know...

Why do electrons closer to nucleus have Less energy than electrons first away? Thanks

So i have a homework question which i can't figure out. Use the saha equation to determine the fraction of hydrogen atoms that are ionised at the centre of the sun (N_II/N_tot) T=15.7x10^6K number density n=6.1x10^31 m^-3 m = mass of electron the saha equation is N_(i+1)/Ni =...

Homework Statement A sample of aluminum oxide, Al2O3(s), contains 8.29*10^25 total atoms. Calculate the amount in moles of aluminum oxide in the sample. Hint: This is a two-step problem. Calculate the number of formula units first.Homework Equations N=N × N_{A} The Attempt at a Solution...

Hello, If we look at a system of two two-level atoms interacting with light, most papers start with a Hamiltonian H_{int}=(\sigma_{1}^{+}+\sigma_{2}^{+})a_{\textbf{k},\lambda} + h.c. That is, we absorb a photon and lost one excitation in the atoms or vice versa. Why do we never...

We know that hydrogen atom has got one electron.But If we look a hydrogen spectrum there are lots of spectral line. How can that be possible? Because in Bohr's atomic model the spectral lınes mean, electrons energy levels.It shows there is possible energy levels which electrons can...

An ideal gas obeys Maxwell Boltzman statistics. Gas atoms have an average kinetic energy of 3kT/2 but the individual atoms have energies that vary from this average (Chi square distributed). A solid (metal) has an average kinetic energy of about 3kT. Does anybody know what statistical...

Regarding the relation between atoms' kinetic energy and the energy levels of their electrons upon excitation: In other words, what really happens when an atom is excited, either by radiation or by collisions, or otherwise ? What are the mechanisms under which the transferred energy goes to...

Homework Statement Two hydrogen atoms, both initially in the ground state, undergo a head-on collision. If both atoms are to be excited to the n = 2 level in this collision, what is the minimum speed each atom can have before the collision? Answer in units of m/s 1 mol of hydrogen is...

Paulis exclusion principle say that two electrons around a nucleus can't have the same quantum number. Does that mean that, say, two hydrogen atoms with electrons with the same spin can't make hydrogen gas? Or does one of the electrons change its spin?

Hello! Long time lurker, first time poster. This is the first of a couple of questions which has totally stumped me, although I have a feeling it's easier than it first seems. Homework Statement A particle is initially located at one of two atoms. The particle is subject to Hhop , a...

We're just been learning about emission and absorption spectra and how these relate to the energy levels of electrons in an atom but its brought up 2 questions. 1. In chemistry our notes say that the energy change between levels gets smaller as you move out from the nucleus, however in...

Wikipedia says that only 3 atoms of Ununoctium ever existed? How can you detect such a tiny quantity of something? How can you distinguish an elements with an half-life of about 0.9 ms or less?

See attachment for working and details of what i have done.

Greetings, My questions below could be categorized into a mixture of “history of chemistry” and “experimental basis for chemistry”. I’m having difficulty phrasing the questions that I have, so I’m going to start by stating them as directly as I can, and then spend the rest of this post...

Homework Statement The ideal gas has a density of 2.4 kgm–3 at a pressure of 2.0 × 105 Pa and a temperature of 300 K.Find the root mean square speed of the gas atoms. Homework Equations p=(1/3)*(Nm/V)*v(squared) The Attempt at a Solution I tried to make v(squared) the subject...

Casual searches for muonic atoms brings up various experiments on muonic hydrogen. The physics of this atom is fairly simple because the muon is just a heavier version of an electron. Has anyone studied atoms with both an electron and a muon around a nucleus, such a helium isotope? In this case...

Atoms are much, much smaller than the wavelength of visible light. Visible light is 4,000 - 7,000 angstroms in wavelength while atoms are ~1-7 angstroms. How can something interact with a wavelength when that wavelength is 10^3 larger than it?

I have an exercise with the following text: Suppose you put both electrons in a helium atom into the n=2 state. What would the energy of the emitted electron be? I have attached the solution to the problem, but I am not sure I understand it. I understand the first part about the total...

Sorry if this post seems short, I had to write it in a hurry. I'm currently reading Leonard Susskind's 'The Cosmic Landscape'. In it, he describes how electrons and protons both emit photons, which is what gives them their charge. The explanation is really awesome, but I have one thing I...

Hey..!Its been a long time since I last posted..Any how I returned.. My question is about mEta stable states in atoms in Lasing Action.Wt actually these states are?And are they justifiable by Bohrs atomic model or Schrodinger Probabilistic orbits?If not then from where these additional states came?

Physics noob here. I was wondering, is there a way to measure time delay between the movement of one part of an atom from another? Is there any?

Hello, i'd just like to know do atoms fuse together the instant that they make contact after overcomming repulsion or does it take time? I've been led to believe that when we touch something we never actually touch it since electrons repel each other and we can't generate enough force to...

This is an arbitrary question Is it possible that regardless of whatever atom is present, a process is used to remove all electrons in the atoms that comprise a specific substance? For example if I had say what I will arbitrarily call "An electron boiler" and I just dump in any house...

Simple and stupid question! A Be atom is traveling with 60 kev kinetic energy and splits into two helium atoms, and the process itself releases 92.2 kev. One helium atom moves at a 30 degree angle with respect to x. find the direction of motion of the second helium atom and find the velocity...

Hi there, I'm looking to find the most probable speed of atoms ejected from an oven. Temp (T) is 900°C (so 1173.15K). The material is aluminium with molar mass 0.027kg mol-1 I've got the formula vmp=√(2kT/m) I'm fine with everything above, but I'm not sure what value to use as...

I understand that there are a lot of exceptions to the octet rule, but why do atoms generally WANT to be filled up with electrons? I asked my chemistry friend about this, he didn't have an answer, so I'm assuming that there is a fundamental answer somewhere in QM.

Author: Wolfgang Demtröder Title: Atoms, Molecules and Photons: An Introduction Amazon Link: https://www.amazon.com/dp/3642102972/?tag=pfamazon01-20 Prerequisities: Contents:

100mbq tc 99 requires how much mo 99? Answer in number of atoms, assume equilibrium conditions: 67/6.4 *1x10^8 = 1 x10^9

Homework Statement For a lattice with a two atoms basis, the two dispersion relations valid for Ka = ±∏ w2 = 2C/M2 and w2 = 2C/M1 Show that under these conditions the lattice acts as two independent lattices (one lattice per each atom) with one of the lattices moving while the other is...

Hi, can someone please tell me how to calculate force which is acting on one atom. Let's look at the crystal of manganese for example, manganese crystal is simple cube (as far I remember) so how can I calculate force acting on one of 8 atom in that crystal? And one more question, it's often...

When two hydrogen atoms that each occupied an estimated amount of space combine in a nuclear fusion, that new atom(helium) actually occupies an estimated less amount of space than even one of the hydrogen atoms...Where does that space go if space actually has weight or energy(Which is what...

I was solving an exercise my teacher asked us, to determinate the hibridization of the molecules. He give the molecule and I have to tell which hibridization it is. I want to know if I can do this to every molecule, I mean, are all molecules in the world hybridized? If so, why do we have to...

Hey guys, Do the quarks determine the element? If I have a atom that has let's say 5 neutrons and 5 protons, and then all of a sudden one of the quarks changes from a down quark to a up quark, this will then change the ratio/amount of protons and neutrons thus changing the element? What...

What happens to the atoms if an object is hit? If I hit my table, will it cause atoms to vibrate more?

Homework Statement find formal charge on P in PBr3 and N in NBrI2 Homework Equations Formal charge = number of valence electrons-number of lone pairs- 1/2 number of bonding electrons The Attempt at a Solution FC on P = 5 - 1 - 3 = 1 FC on N = 5 - 1 - 3 = 1 these are wrong for...

Hi, I have read about electric charge and tried to understand one particular thing but still couldnt: If we positively charge a big metal plate with very high voltage and approach to it a small solid neutral metal sphere, the smaller sphere obviously will get attracted, i.e. a force will...

Homework Statement If you have atoms that are normally located at the normal lattice positions or at an interstitial position where energy >ε, how can I find the probability that n interstitial positions are occupied by atoms? If we were to use large N how can I find the fraction of...

Why Doesn't the increase in mass of the electrons, due to the relativistic correction required to prevent the calculated electron speed exceeding the speed of light, increase the mass of the atoms of the large elements? If the electrons were heavier on larger elements then the mass would diverge...

My advanced statistical mechanics prof told me that it wouldn't make any physical sense to allow N (the number of particles in a system) to be negative. But, somehow, I think that this possibility should be theoretically left open; perhaps there are some systems whose statistical behavior would...