Heyy, If someone please can help me....why does in C and B....the order is π2p and then comes sigma 2p??? In molecules like Oxygen its the other way around.....my teacher is constantly asking why is that?? Please help....I'm desperate....
Thank You for a great lecture, topic explained in a simplest way possible, but not simpler as probably Einstein used to say. Even me understood although I always had a fear before orbitals hybrydization topic, probably never been explained so clearly. Greetings!
Hello sir plz help me 🥺🥺🥺 why water is diamagnetic ?? I found that it contains two unpaired electrons in its last molecular orbital .so it is not paramagnetic .plz elaborate it
Thank you for the great video on MOT. You are awesome! I have been struggling to understand it for the past few days now and everything I read about it just never really "clicked." You explained molecular orbital theory very thoroughly and with great detail. I was finally able to understand it properly now. I have my chapter exam tomorrow and final next week so I feel pretty confident now :)
The present work shows the inapplicability of the Pauli principle to chemical bond, and a new theoretical model of the chemical bond is proposed based on the Heisenberg uncertainty principle. See pp. 88 - 104 Review. Benzene on the Basis of the Three-Electron Bond. (The Pauli exclusion principle, Heisenberg's uncertainty principle and chemical bond). vixra.org/pdf/1710.0326v2.pdf The Pauli exclusion principle and the chemical bond. The Pauli exclusion principle - this is the fundamental principle of quantum mechanics, which asserts that two or more identical fermions (particles with half-integral spin) can not simultaneously be in the same quantum state. Wolfgang Pauli, a Swiss theoretical physicist, formulated this principle in 1925 [1]. In chemistry exactly Pauli exclusion principle often considered as a ban on the existence of three-electron bonds with a multiplicity of 1.5, but it can be shown that Pauli exclusion principle does not prohibit the existence of three-electron bonds. To do this, analyze the Pauli exclusion principle in more detail. According to Pauli exclusion principle in a system consisting of identical fermions, two (or more) particles can not be in the same states [2]. The corresponding formulas of the wave functions and the determinant are given in the reference (this is a standard consideration of the fermion system), but we will concentrate our attention on the derivation: "... Of course, in this formulation, Pauli exclusion principle can only be applied to systems of weakly interacting particles, when one can speak (at least approximately on the states of individual particles) "[2]. That is, Pauli exclusion principle can only be applied to weakly interacting particles, when one can talk about the states of individual particles. But if we recall that any classical chemical bond is formed between two nuclei (this is a fundamental difference from atomic orbitals), which somehow "pull" the electrons one upon another, it is logical to assume that in the formation of a chemical bond, the electrons can no longer be regarded as weakly interacting particles . This assumption is confirmed by the earlier introduced notion of a chemical bond as a separate semi-virtual particle (natural component of the particle "parts" can not be weakly interacting). Representations of the chemical bond given in the chapter "The Principle of Heisenberg's Uncertainty and the Chemical Bond" categorically reject the statements about the chemical bond as a system of weakly interacting electrons. On the contrary, it follows from the above description that in the chemical bond, the electrons "lose" their individuality and "occupy" the entire chemical bond, that is, the electrons in the chemical bond "interact as much as possible", which directly indicates the inapplicability of the Pauli exclusion principle to the chemical bond. Moreover, the quantum-mechanical uncertainty in momentum and coordinate, in fact, strictly indicates that in the chemical bond, electrons are a system of "maximally" strongly interacting particles, and the whole chemical bond is a separate particle in which there is no place for the notion of an "individual" electron, its velocity, coordinate, energy, etc., description. This is fundamentally not true. The chemical bond is a separate particle, called us "semi-virtual particle", it is a composite particle that consists of individual electrons (strongly interacting), and spatially located between the nuclei. Thus, the introduction of a three-electron bond with a multiplicity of 1.5 is justified from the chemical point of view (simply explains the structure of the benzene molecule, aromaticity, the structure of organic and inorganic substances, etc.) is confirmed by the Pauli exclusion principle and the logical assumption of a chemical bond as system of strongly interacting particles (actually a separate semi-virtual particle), and as a consequence the inapplicability of the Pauli exclusion principle to a chemical bond. 1. Pauli W. Uber den Zusammenhang des Abschlusses der Elektronengruppen in Atom mit der Komplexstruktur der Spektren, - Z. Phys., 1925, 31, 765-783. 2. A.S. Davydov. Quantum mechanics. Second edition. Publishing house "Science". Moscow, 1973, p. 334. Heisenberg's uncertainty principle and chemical bond. For further analysis of chemical bond, let us consider the Compton wavelength of an electron: λc.е. = h/(me*c)= 2.4263 * 10^(-12) m The Compton wavelength of an electron is equivalent to the wavelength of a photon whose energy is equal to the rest energy of the electron itself (the standard conclusion is given below): λ = h/(m*v), E = h*γ, E = me*c^2, c = γ*λ, γ = c/λ E = h*γ, E = h*(c/λ) = me*c^2, λc.е. = h/(me*c) where λ is the Louis de Broglie wavelength, me is the mass of the electron, c, γ is the speed and frequency of light, and h is the Planck constant. It is more interesting to consider what happens to an electron in a region with linear dimensions smaller than the Compton wavelength of an electron. According to Heisenberg uncertainty in this area, we have a quantum mechanical uncertainty in the momentum of at least m*c and a quantum mechanical uncertainty in the energy of at least me*c^2 : Δp ≥ mе*c and ΔE ≥ me*c^2 which is sufficient for the production of virtual electron-positron pairs. Therefore, in such a region the electron can no longer be regarded as a "point object", since it (an electron) spends part of its time in the state "electron + pair (positron + electron)". As a result of the above, an electron at distances smaller than the Compton length is a system with an infinite number of degrees of freedom and its interaction should be described within the framework of quantum field theory. Most importantly, the transition to the intermediate state "electron + pair (positron + electron)" carried per time ~ λc.е./c Δt = λc.е./c = 2.4263 * 10^(-12)/(3*10^8) = 8.1*10^(-20) s Now we will try to use all the above-mentioned to describe the chemical bond using Einstein's theory of relativity and Heisenberg's uncertainty principle. To do this, let's make one assumption: suppose that the wavelength of an electron on a Bohr orbit (the hydrogen atom) is the same Compton wavelength of an electron, but in another frame of reference, and as a result there is a 137-times greater Compton wavelength (due to the effects of relativity theory): λc.е. = h/(me*c) = 2.4263 * 10^(-12) m λb. = h/(me*v)= 2*π*R = 3.31*10^(-10) m λb./λc.е.= 137 where R= 0.527 Å, the Bohr radius. Since the De Broglie wavelength in a hydrogen atom (according to Bohr) is 137 times larger than the Compton wavelength of an electron, it is quite logical to assume that the energy interactions will be 137 times weaker (the longer the photon wavelength, the lower the frequency, and hence the energy ). We note that 1 / 137.036 is a fine structure constant, the fundamental physical constant characterizing the force of electromagnetic interaction was introduced into science in 1916 year by the German physicist Arnold Sommerfeld as a measure of relativistic corrections in describing atomic spectra within the framework of the model of the N. Bohr atom. To describe the chemical bond, we use the Heisenberg uncertainty principle: Δx * Δp ≥ ћ / 2 Given the weakening of the energy interaction 137 times, the Heisenberg uncertainty principle can be written in the form: Δx* Δp ≥ (ћ * 137)/2 According to the last equation, the quantum mechanical uncertainty in the momentum of an electron in a chemical bond must be at least me * c, and the quantum mechanical uncertainty in the energy is not less than me * c ^ 2, which should also be sufficient for the production of virtual electron-positron pairs. Therefore, in the field of chemical bonding, in this case, an electron can not be regarded as a "point object", since it (an electron) will spend part of its time in the state "electron + pair (positron + electron)", and therefore its interaction should be described in the framework of quantum field theory. This approach makes it possible to explain how, in the case of many-electron chemical bonds (two-electron, three-electron, etc.), repulsion between electrons is overcome: since the chemical bond is actually a "boiling mass" of electrons and positrons, virtual positrons "help" overcome the repulsion between electrons. This approach assumes that the chemical bond is in fact a closed spatial bag (a potential well in the energy sense), in which "boiling" of real electrons and also virtual positrons and electrons occurs, and the "volume" of this potential bag is actually a "volume" of chemical bond and also the spatial measure of the quantum-mechanical uncertainty in the position of the electron. Strictly speaking, with such a consideration, the electron no longer has a certain energy, momentum, coordinates, and is no longer a "point particle", but actually takes up the "whole volume" of chemical bonding. It can be argued that in the chemical bond a single electron is depersonalized and loses its individuality, in fact it does not exist, but there is a "boiling mass" of real electrons and virtual positrons and electrons that by fluctuate change each other. That is, the chemical bond is actually a separate particle, as already mentioned, a semi-virtual particle. Moreover, this approach can be extended to the structure of elementary particles such as an electron or a positron: an elementary particle in this consideration is a fluctuating vacuum closed in a certain spatial bag, which is a potential well for these fluctuations. See pp. 88 - 104. Review. Benzene on the Basis of the Three-Electron Bond. (The Pauli exclusion principle, Heisenberg's uncertainty principle and chemical bond). vixra.org/pdf/1710.0326v2.pdf Bezverkhniy Volodymyr (viXra):vixra.org/author/bezverkhniy_volodymyr_dmytrovych
Better than my teacher, if only American society valued education we wouldn't have to pay thousands of dollars just to have to come to a free service such as RU-vid in order to learn. But I'm glad to know that you helped me, thank you.
Great vid, but i was looking for a more advanced video on MO theory, one that includes d orbitals and constructing polyatomic MOD's with SALCs. Any suggestions?
* just avoid putting music at the begining of the video , it doesn't make it awkward trust me ! Don't need to worry ! As for tge ads , a lot of time there is inappropriate content so you could be earning sins , but May Allah subhanahu wa ta'ala protect you from that , make it easy for you and erase all your sins , Ameen ya Rabbi btw Jazzaka Allah khairan professor !
Thank you so much it helped me alot. But I'm having some doubts. Do the remaining atoms in the periodic table have any molecular orbital diagrams and if it is a yes then are they similar to oxygen to fluorine type of MOD's or like lithium to nitrogen type..?
