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The electron density is proportional to the square of the wavefunction. More precisely it's: $$D \propto \Psi\Psi^*$$ where $\Psi^*$ is the complex conjugate of the wavefunction. The wavefunction can be complex, but the product $\Psi\Psi^*$ is always real, which is just as well since the electrons are real too. So a diagram of the electron density looks ...

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It amuses me how often the cart is set in front of the horse in answers at this site. It is the data that drive theoretical formulations, not theoretical formulations the data. It was from the spectral lines of the hydrogen atom that the Schrodinger equation was established and the whole construct of the theory of quantum mechanics took off. The series ...

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No, you cannot hear the shape of the drum. Even if you have a list of the eigenvalues of the Hamiltonian, you cannot reconstruct the Hamiltonian. For example, these two Hamiltonians have the same eigenvalues: The spectral line is the same for both systems. Assuming that the transition is from energy 2 to energy 1, the first system goes from a state that ...

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In practice it would be very difficult to truly reconstruct "the" wave-function from the spectra. For one thing: Which wave function? Measured spectral emission/absorption are the result of transitions between states (ground and excited, e.g.) and these states all have their own wavefunctions. Furthermore, a typical measured spectrum is measured over a ...

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It is called combustion, and it happens in materials which have a lower energy content when their component molecules join with the oxygen in the atmosphere, than when in a solid/liquid structure. When energy is given to start the fire the piece of coal burns and releases energy with excess enough to sustain the reaction and leave heat energy for use. ...

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Usually in conductors we think of mobile charge carriers as being electrons, but in an aqueous solution they can be ions. The two different ions have different affinities for electrons and therefore end up with different, non-zero charges, which move in response to an electric field. In the crystal state, there are no free electrons, because the energy level ...

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Can this frozen form freeze further? Or can it become more solid? (for example, by exposing to colder temperatures and/or a higher pressure). Can ice freeze further by transforming into a different crystalline form? The ice will remain solid while lowering temperature or pressure but might change in state, or phase, as you mention. But you should ...

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Tungsten filaments are hot. They very slowly evaporate. Atoms of tungsten come flying off the hot surface and stick to the cold envelope of the bulb. Eventually the bulb darkens. Also eventually a spot on the filament gets thin. The same current flows through the thin spot. So this spot gets hotter than the rest of the filament. This increases the rate of ...

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