Physics help please - allowed and forbidden transitions :)?
the final mindset of physicists is definitely to think approximately that the universe has policies or rules, and that they humbly artwork to wager them. whilst they locate some rule that looks, to make sense, they call it a theory, and that they war to infer its consequences. an significant area of the scientific interest is to study no count if the implications do ensue genuinely. If some do no longer, it skill that the assumption might desire to be incorrect, and that yet another one must be discovered. A forbidden transition is a metamorphosis of states that's predicted in no thank you to ensue via the policies considered valid on the 2nd. in case you word a forbidden transition, it fairly is super information because of the fact you proved that those policies are incorrect, and that new concepts must be discovered. it fairly is like taking an alpinisit to the foot of a in no way climbed top. exhilaration! Now, an significant element. as quickly as I say 'humbly', it does no longer recommend that as human beings, we'd desire to continuously be embarrassed approximately our lack of awareness, and that we'd desire to continuously punish ourselves from some meant previous arrogance in besides. this variety of line of although is a the remainder of an 'unique sin' culpability form of mindset. This has no longer something to do with technology. as quickly as I say humbly, it fairly is because of the fact the job is extremely difficult, and consequences purely short-term. it fairly is been a mutually as because of the fact the self-obvious policies of nature have been understood and integrated in everybody's mindset to actuality. the subsequent steps are patently no longer obtrusive, and each scientist is conscious that his findings, in spite of the fact that excellent quicker or later in time, would be puzzled and altered quicker or later. Newton replaced Aristotles, Einstein replaced Newton, and the sequence shop on in spite of the fact that now artwork is greater via communities than via persons. Now, there is not any disgrace for lack of awareness. you do no longer blame a baby for being a baby. you purely artwork to help it strengthen up. We purely artwork to help wisdom strengthen. it quite is a in no way-ending tale.
Forbidden transitions and allowed transitions?
The general attitude of physicists is indeed to consider that the universe has rules or laws, and that they humbly work to guess them. When they find some rule that seems, to make sense, they call it a Principle, and they try to deduce its consequences. An important part of the scientific activity is to check whether the consequences do occur actually. If some don't, it means that the principle could be wrong, and that another one has to be found. A forbidden transition is a change of states which is predicted never to happen by the rules considered valid at the moment. If you observe a forbidden transition, this is great news because you proved that those rules are wrong, and that new Principles have to be found. It's like taking an alpinisit to the foot of a never climbed peak. Excitement! Now, an important point. When I say 'humbly', it does not mean that as humans, we should be ashamed of our ignorance, and that we should punish ourselves from some supposed past arrogance whatsoever. This kind of line of though is a remainder of an 'original sin' culpability kind of attitude. This has nothing to do with science. When I say humbly, it is because the task is exceedingly difficult, and results only temporary. It's been a while since the self-evident rules of nature have been understood and integrated in everyone's approach to reality. The next steps are clearly not obvious, and every scientist knows that his findings, however glorious at some point in time, will be questioned and replaced sooner or later. Newton replaced Aristotles, Einstein replaced Newton, and the series carry on although now work is more by communities than by individuals. Now, there is no shame for ignorance. You don't blame a baby for being a baby. You just work to help it grow up. We just work to help knowledge grow. It's a never-ending story.
What is a d-d transition?
Consider a transition metal, M, (i.e., has a partially filled d AO in one of its common oxidation states) in a [MCl4]^n- (n = 0,1, 2) cmplx or cmplx ion. In the tetrahedral environment of the four Cl^- ligands (the tetrahedral ligand- or crystal- field) the (3)d AOs do not have the same energy (they are not degenerate). The 3d AOs are split into a lower energy set of two d AOs (dx^2-y^2; dz^2) known as the e set and a higher energy set of three d AOs (dxy, dxz, dyz) known as the t set. The energy gap between the e and t orbitals occurs in the visible range: e↑ t2 0 → hν → e 0 t2↑ with ν in the visible range. This is called a d-d (electronic) transition. The color observed (by reflection or transmission) from the cmplx ion is the COMPLEMENTARY color to that being absorbed. So if the cmplx absorbs red the soln with the ion will appear blue. NO emission is involved. So for a first approximation to observe a d-d transition you must have a d e- in the e set that can be promoted to a vacant t AO (a hole if you like). Now let’s consider your cmplxs. I hope you know how to calculate number of d e-s a TM has in a given oxidation state. TiCl4: Ti(IV) no (3)d e-s, no d-d transitions possible; cmpd is colorless. [VCl4]^- : V(III) 3d^2 (e^2 t^0) d-d transition possible e^2 t^0 → hν → e^1 t^1 cmplx is colored. [CrCl4]- Cr(III) 3d^3 (you can work this out now), [MnCl4]^2- (special case) Mn(II): 3d^5 e^2(↑↑) t^3(↑↑↑) can you see that in this case for an e → t transition to take place the e- must change its spin; it is called a spin-forbidden transition and the probability for the transition is low and so Mn(II) are almost colorless. [FeCl4]^-: Fe(II) e ^3 t^3 d-d allowed so it is colored. [CoCl4]-: Co(III) e^3 t^3 (same as previous case). [NiCl4]^- this is a mistake it should be [NiCl4]^2-: Ni(II) d^8 e ^4 t^4 d-d allowed, colored [CuCl4]^- (actually it is a distorted tetrahedron) d^9 e ^4 t^5 d-d allowed colored. Bonus: [ZnCl4]^2- d^10 no d-d transitions allowed: colorless. For another day octahedral ligand fields; order inverted and can have high and low spin cases. Tetrahedral cmplx are always high spin because the energy gap Δtet is small. See F. A. Cotton, G. Wilkinson, P. L. Gaus, Basic Inorganic Chemistry 3rd ed. p 516
What is the wavelength of this transition?
Wavelength..... An electron goes from n=4 to n=3, a difference of 1.06x10^-19J. This indicates that the n=4 and n=3 energy levels are separated by a discrete amount of energy, leading to the conclusion that the electrons are in discrete energy levels. For such a case the energy of the electron must be quantized, that is, the electron can only have certain discrete energies, and exist in discrete energy levels, not just anywhere in an atom. The quantized nature of the electron shows up as a line spectrum where each line represents the transition of an electron from one allowed quantized state to another. Otherwise we would see a continuous spectrum. An electron with quantum numbers of n = 5, ℓ = 0, mℓ = 0, ms = -1/2 is found in the a 5s orbital. Four quantum numbers: n = principal quantum number = major energy level. ......Values are 1, 2, 3, .... ℓ = azimuthal quantum number = energy sublevel. ......Values are 0 to n-1. s=0, p=1, d=2, f=3 mℓ = magnetic quantum number = the orbital in the sublevel. .........Values are -ℓ ..0.. +ℓ ms = spin quantum number = electron in orbital .........Values are +½ or -½
What is Quantization of Energy?
The theory of the Quantization of Energy states that all energy in nature occurs in finite "bundles" and energy can only increase by whole increments thereof. No fractions are possible, the same way that you can't give somebody less than 1 cent because 1 cent is the smallest unit of our currency. In 1900, a German scientist named Max Planck wrote an equation to show the relationship between energy and frequency of electromagnetic radiation: E = hn where E is the energy of a bit of light called a quantum or a photon. This is the smallest unit of electromagnetic radiation that can be emitted, and is essentially a small “packet” of energy. The “h” in the above equation is a very small constant called “Planck’s constant” (6.626068 × 10-34 J s) and “n” is the frequency of the radiation. Planck's “quantum” idea became the basis for the modern understanding of atomic structure. In the above equation, as the frequency of radiation increases, its energy increases by the increment “h”. In other words, energy is not continuous; it is quantized and only certain energies are allowed. Continuous energy and quantized energy can be likened to a ramp versus a set of stairs connecting two levels of a building. The ramp is analogous to continuous energy – you can sit at any position along the ramp and thus be at any elevation between the two levels. The stairs are analogous to quantized or discrete energy – you can only sit at certain elevations between the two levels and nowhere in between. You may sit only on the steps, not in between the steps. Only certain elevations are allowed, the same way that only certain energy levels are allowed in nature. I hope this helps! Good luck!
Which of the following transitions in the sodium atom is allowed ?
Na - atomic number 11. 1s - 2 e- 2s - 2 e- 2p - 6 e- 3s - 1 e- Stable state. When a sodium atom gets excited, the electron furthest out jumps to the corresponding shell depending on the energy input. When it drops back down again to it's stable state (lowest energy state) - it emits a photon. Your answer is C - because 3s goes to 3p and then drops back down to 3s. Not only is this the correct answer, it is the only one that makes sense because the other shells definitely don't correspond and don't make any sense. I hope this helps. Cheers.
Identify the type of energy transition occurring in an atom that causes...?
In general terms, it is the falling of an electron from a higher to a lower energy level.
In spectroscopy, why are some transitions called “forbidden” if they are still observed?
Great question!My understanding of this is (other Quorans, correct me if I am wrong) is that real work effects cause a slight mixing of upper and lower wave function states.In more understandable terms, these transitions can be approximated by an exactly solvable quantum mechanical model. For example the vibration (in and out) of a diatomic molecule like O2 can be approximated by two bodies attached by a spring. Ideally if the oxygen atoms are separated slightly beyond their equilibrium position, the will experience a restoring force proportional to their displacement. Given this, the Shrodinger wave equation can be solved to yield eigenfuntions in the form of pure Hermite polynomials. Working out the math to calculate transition probabilities, the orthogonality of Hermite polynomials means that only certain transitions will have a non zero probability of happening - hence allowed states.This result implies that the underlying premise is correct. However, body and spring model for oxygen is only an approximation. If the atoms get very close they will experience a larger restoring force. If they get very far they will experience a smaller restoring force. This means that the eigenfunctions are no longer pure Hermitian polynomial, but a mixture of states. When working out the math with mixed states, you get a small, but non zero probability of forbidden transitions occurring.I hav given one example, but this can occur in many ways. Electronic transitions in atoms and molecules are approximated by the hydrogen atom model, but things like the presence spins and motion of other particles in the system can induce he same effect. Rotational spectra of molecules are approximated by a rigid rotor model, but effects relating to the shape and motion of the molecule can also induce cross terms.
Transition states..please help!!?
Which of the following is an allowed transition? a. l=1; ml=0 to l=1; ml=1 b. l=1; ml=0 to l=1; ml=-1 c. l=1; ml=0 to l=2; ml=2 d. l=1; ml=0 to l=2; ml=0 Which of the following is a forbidden transition? a. l=3; mi=2 to l=2; ml=2 b. l=3; mi=2 to l=2; ml=0 c. l=3; mi=2 to l=4; ml=3 d. l=3; mi=2 to l=2; ml=1 In the Zeeman effect, the energy levels of hydrogen are split by a magnetic field. Each state with a different value of has a different energy. The differences in energy between adjacent values of are all equal. The Zeeman effect is observed as a splitting in the spectral lines of hydrogen in the presence of a magnetic field. What is the greatest number of lines that a single spectral line can be split into by a magnetic field?
What is the change in internal energy?
internal energy(U)=heat supplied to system(Q)-work done by system(W). Here Q=100 J since compressing the gas is equivalent to a rise in heat energy and W=100 J since it allows heat to escape, it is equivalent to the gas doing work. So, add them together and you get 0. So, answer's 1