- #1
AbedeuS
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Hello, I'm usually a PF user in General Physics/Chemistry, but I might need the help of you quantum physics users :), recently I have started a quantum chemistry module and I'd appreciate if I could clear some stuff up with you guys rather than look like a penis by asking all my friends, who probably don't understand as much as me either anyway.
Not quantum (but appeared in the quantum chem bit)
Now I've used the coulomb equation for about 3 years now, but It's always been slightly confusing for me, so just to clear it up:
V_{potential energy} = \frac{Q_{1}Q_{2}}{4\pi\epsilon_{o}r}
We have this (non-quantum) equation, sorry for ramming it in here, but I'd rather not spam by posting two threads, and this is probably basic for most of you guys, now for this equation. Let's say I have a proton and an electron, the maximum potential energy that they can have is "ZERO" (infinite separation) and their lowest potential energy is negative "Infinity", so when an electron has potential energy of, say, -30eV, this would be equal to saying, if I gave the electron 30eV it would become infinitely separated and have maximum potential energy?
Likewise for two alike charges (two positive) the maximum potential energy is Positive infinity and the lowest is Zero, so if I gave two Protons infinite energy they should be able to meld into eachover (lets not go into details, I'm just going to guess there's a limitation to how close they get before binding).
Translational Motion
Heres one that was pulled up in the lecture, translational motion was represented by a wavefunction, now I understand that Atoms will move in a "Wavelike" manner represented by the wavelength:
\lambda=\frac{h}{m}
but don't they have a particular position in space, mapping translational motion as a wavefunction would have massive implications for diffusion, gas velocity between two pressures and such, how does Quantum theory work around this?
Uncertanty theory
Now the lecturer just said uncertainty theory means we can't be sure about anything (which is true), If i could have a go at the explanation around the uncertainty theory, if I wanted to localise the postion of a particle exhibiting a wavefunction, such as an electron, I would have to superimpose a sympathy of waves over it until the interference pattern divulged a particular position in the wavefunction where the proabability of it existing in the position is extremely high, but by this series of superpositions we cannot find out the momentum of the said wavefunction? Or is the equation:
m * p = \frac{h}{4\pi}
Where m and p are uncertanties of these quantities, i used an equals sign rather than an inequality sign because, I'm a newbie with Latex :)
Sorry for the hassle, but, your probably used to it so...*pokes your brain with a stick*
Not quantum (but appeared in the quantum chem bit)
Now I've used the coulomb equation for about 3 years now, but It's always been slightly confusing for me, so just to clear it up:
V_{potential energy} = \frac{Q_{1}Q_{2}}{4\pi\epsilon_{o}r}
We have this (non-quantum) equation, sorry for ramming it in here, but I'd rather not spam by posting two threads, and this is probably basic for most of you guys, now for this equation. Let's say I have a proton and an electron, the maximum potential energy that they can have is "ZERO" (infinite separation) and their lowest potential energy is negative "Infinity", so when an electron has potential energy of, say, -30eV, this would be equal to saying, if I gave the electron 30eV it would become infinitely separated and have maximum potential energy?
Likewise for two alike charges (two positive) the maximum potential energy is Positive infinity and the lowest is Zero, so if I gave two Protons infinite energy they should be able to meld into eachover (lets not go into details, I'm just going to guess there's a limitation to how close they get before binding).
Translational Motion
Heres one that was pulled up in the lecture, translational motion was represented by a wavefunction, now I understand that Atoms will move in a "Wavelike" manner represented by the wavelength:
\lambda=\frac{h}{m}
but don't they have a particular position in space, mapping translational motion as a wavefunction would have massive implications for diffusion, gas velocity between two pressures and such, how does Quantum theory work around this?
Uncertanty theory
Now the lecturer just said uncertainty theory means we can't be sure about anything (which is true), If i could have a go at the explanation around the uncertainty theory, if I wanted to localise the postion of a particle exhibiting a wavefunction, such as an electron, I would have to superimpose a sympathy of waves over it until the interference pattern divulged a particular position in the wavefunction where the proabability of it existing in the position is extremely high, but by this series of superpositions we cannot find out the momentum of the said wavefunction? Or is the equation:
m * p = \frac{h}{4\pi}
Where m and p are uncertanties of these quantities, i used an equals sign rather than an inequality sign because, I'm a newbie with Latex :)
Sorry for the hassle, but, your probably used to it so...*pokes your brain with a stick*