Hello all, I want to know that:- 1. Whether photons leaves some trace or effect or information on its absorption & remmition from any atom or molecule? 2. Whether molecules of all substances always absorb & re-emit photons exposed to them or 'energy moves from higher level to lower level' applies in this context? 3. When a atom/molecule absorb a photon its electron are exited & shift to next orbit & will then decays back to origional orbit. Now my question is: How many photons will be re-emitted by this shift on exitation & if there can be differance in strength/value of photons emitted on shift of electron to higher orbit & on decaying back? Furthur, Is there a orbit shift to lower than origional orbit possible & if possible how & what type of photons it will be emit? Best wishes.
Hello Kumar, It leaves the atom or molecule in a different quantum state than before the absorption or emission. If exposed to light of the right frequency, molecules will absorb the light, making the molecule go to a higher energy state. There are two emission processes: spontaneous emission and stimulated emission. The most common is spontaneous emission, which is where molecules at higher energy levels spontaneously emit photons to return them to their ground energy states. When an atom falls back to its ground state, it can do so either in one step, emitting a single photon, or, if their are intermediate energy levels available between the excited state and the ground state, it can emit several photons, each one carrying energy corresponding to the "jump" in energy made by the atom when it released that photon. Best wishes.
James R, Thanks,Thanks for reply & best wishes. "It leaves the atom or molecule in a different quantum state than before the absorption or emission." I meant when photon absorbed & re-emitted? Will this absorption & re-emission of photon(not just absorption or emission) by atom/molecule will leave some traces/effect on atom/molecule which so experianced absorption & re-emission? ill the re-mitted photon be differant somewhat than the photon absorbed? I think it may be linked to photo-degradation/upgradation. How does molecules comosed of atoms having low atomic number/weight as water, interact with most of the photons emmited by most of salts?
No. There will be no traces left on the atom, and the emitted photon will be the same as the absorbed one. The only caveat is that the photon is emitted in a random direction. What's photo-degradation? I don't know. It would depend on the energy levels of water molecules, compared to salt molecules.
Then what is purpose of this absoption & remission of photons? Nature might had not made anything purposeless. I mean same--atoms/molecules effected by light. But can water(or H,C,O atoms or atoms with lower atomic numbers in comparisn to higher) be an universal/major absorbant for all or most type of photons?
If you are referring to reactions stimulated by light, such as the decomposition of silver halides in visible light (the original basis of photography), or the formation of Cl free radicals from CFCs due to UV photons, then it is not really affecting the atoms themselves, just giving them enough energy to react. There are lots of things that have no purpose - it doesn't make them any less real. To use a chemistry analogy, the self dissociation of water might be termed pointless, as the water is neutral, but it still occurs.
geodesic, Thanks anyway one purpose has come to my mind i.e. spread or dispersal of light by reflection, refraction etc. Is it correct? Still, it does not looks logically correct that photons do not effect permanentaly or leave any information on atoms/molecules on their travel/exchange through these.
Hello, If we think logically, what can be the prime reason of change, modification or degradation of any substance at its quantum level? Can two atoms or molecules of same element or substance be differant in any way(not isotopes) from each other? Please Register or Log in to view the hidden image! Btw, what happens when electron goes to lower level on emitting photons? Does it remain there or instantly absorb other photon?
Kumar, What makes you think that? You have probably noticed that water is transparent. The fact that you can see through water means that it doesn't absorb much visible light. Hence, it is not a "univeral absorbant". What kind of traces are you imagining? And why do you think there should be any? If you take two water molecules, for example, they are in all respects identical. There is no test you can do which will show that one is different from another. If you swap the oxygen atom from one molecule to the other, for example, you won't be able to do any test afterward which showed they were swapped. The atoms are indistinguishable. It will only absorb photons if (a) there are photons in the vicinity to be absorbed, and (b) the photons have just the right energy which corresponds to a quantum transition in the substance in question. The amount of time taken before absorption occurs depends on the ratio of photons to atoms.
James R, Are sun-burns not related to this effect i.e.exchange of photons? Although this exchange indicate purpose as 'spread of light by refraction,reflection..& travel throught a media, still I think it should leave some traces/effect which in long run should be the prime reason of change & modification at most basic level. Still, light slow down,refraction or photons exchange occurs in water. How? Does "absorb" here mean, media keeps any visible light's photons but water don't? Suppose, we dissolve salt NaCl in water & mix/shake it thoroughly, will then photons of both NaCl & water molecules be emited & exchanged by molecules of NaCl & water or not? Since energy travels from higher to lower,I think Nacl's photons can travel to water's molecules. What does it mean "Molecular Absorption of photons"? Can photons be absorbed directly in molecules effecting its inter or intra molecular forces without effecting its atoms?
Kumar, Your skin absorbs ultraviolet photons from the Sun. This means that atoms in your skin jump to higher energy states. However, they do not only lose that energy by emitting light. They can also lose it by colliding with other atoms and molecules. The UV light can also break bonds between molecules, causing damage to skin cells. The absorption of light can obviously produce flow-on effects on things. But it ultimately leaves no traces on the atoms themselves, since the energy is eventually spread to other things. The delay involved in absorbing and reemitting photons in water causes the effective speed of light in water to slow, which leads to all the refractive effects we see. Yes. If light is absorbed, its energy is converted to other kinds of energy. If it is not absorbed, the energy remains in the form of light. The ones which correspond to energies in both water and NaCl can be exchanged. Yes. Molecules have their own energy levels, determined by the electrical interactions of the atoms making up the molecules. When a photon is absorbed by a molecule, it can break chemical bonds, or cause the molecule to rotate or vibrate faster than before.
If lower energy levels are available, then electrons will ordinarily spontaneously fall to those lower energy levels after a short time, emitting photons. No. Molecules consist of atoms. If you affect a molecule, you are necesarily affecting the atoms which make up the molecule. It just depends on which level you want to look at things - the molecular level or the atomic level.
If lower enegy levels are availabe, is it possible to keep electrons or they can remain at lower enegy levels than origional normal level for long after they fall to those lower energy levels after a short time, emitting photons. On other side, can we keep or maintain higher energy level than normal level(means exitation) for long under normal environment. What about inter or intra molecular forces, can't these also not been effected by photons-molecular interactions without effecting structure of atoms in molecules.
Please Register or Log in to view the hidden image! James, Under above effect, is it possible that electrons of water & NaCl can be exchanged on mixing & shaking?
James, Sorry to keep you involved. Thanks for replies. I just got this link:- http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1675269&dopt=Abstract
Can you tell me the following:- 1. Can/are differant photons(all or most) be differant from each other in their property in all or in some groups? 2.What can be the minimum or maximum vicinity of photons for absorption by atoms? 3. Are all types of waves other than photons can also travel through atoms/molecules as photons travels? 4. Do the photons/waves absorbed/emitted can be specific to molecules also? I mean can molecules possess,emit or absorb photons/waves of specific properties specific to those not specific to their constituted atoms or can photons/waves be emitted or ansorbed with mixed properties representing any molecule?
Hello James, Pls reply some questions. Furthur, In respect of your reply:"It will only absorb photons if (a) there are photons in the vicinity to be absorbed, and (b) the photons have just the right energy which corresponds to a quantum transition in the substance in question." If right/specific energy is required for quantum transition how we all hear sound waves, feel other waves & feel radiation/heat from photons, similarily? Are we ll not differant in substance? How then correspondance of right energy takes place or correct? Sorry, but I need to know this aspect badly, for pursual of discussions at: http://www.sciforums.com/showthread.php?t=42019
Just for general information: Kumar is running this on a number of forums. He is trying to find scientific vindication for homeopathy. His present thesis is that when shaking a solution, photons from the solute leave an imprint on the medium. Several people have tried, so far in vain, to explain why this does not happen. Unfortunately, Kumar thinks that scientific terms can be cherry-picked at random and assembled in whichever way you please, as long as it supports your belief. Hans :bugeye:
