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You could think of this in terms equilibrium processes. The shower increases the partial pressure of water in air and that pushes the equilibrium of water condensing on the surface in the forward. There may also be some capillary action if the adsorbed water can form small liquid droplets. As more water seeps into the tissue the stress-strain properties of ...

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Molecules are not that large. The density of air at 1 Atm and 20°C is $2.5\times 10^{25}$ m$^{-3}$. So, the average spacing, using your teacher's method, is about $(2.5\times 10^{25})^{-1/3} = 3.4$ nm. The radius of molecular nitrogen is 0.2 nm. So, the diameter is about 0.4 nm. The means that only about $(0.4/3.4)^3 = 0.0016$ of the volume of air is ...

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If you mean that the photon energy can be converted to excitation of the nuclear motion of the atoms that make up the molecule than the answer to the first part of your question is yes. Molecules rotate and vibrate at discrete energies and by absorption of a photon of the correct energy (typically in the infrared or millimeter to microwave range of the ...

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Within the Born-Oppenheimer Approximation the different species have the same structure as all nuclei are considered to be infinitely heavy. In fact, you can determine the structure of simple molecules by changing one of the atoms with one of its isotopes (a so-called isotopologue of your initial molecule) and comparing the rotational spectra. Of course the ...

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The answer is of course that the material involved has to have some channel through which it interacts with that electromagnetic wave - at its most basic, the material needs to be able to absorb the radiation. You specifically ask about infrared radiation. The photons of infrared radiation (radiation is emitted and absorbed in quanta called photons) have ...

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Many people have the misconception that only infrared radiation creates heat. Actually electromagnetic radiation over all frequencies carries energy. The shorter the wavelength, the higher the energy. Different elements and compounds (or molecules and atoms) have different resonant frequencies and so electromagnetic radiation of the same frequency tends to ...

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Let us consider one of the rotational degrees of freedom of a molecule. Let us assume that the moment of inertia for the relevant principal axis is $I$. Then we can get the spacing of energy levels for this degree of freedom from the quantization rule $I\omega=n\hbar$ (I omit some constant factors and neglect some other things here and everywhere else), so ...

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The OP is mixing up some terminology. When we talk of frozen modes, we don't usually mean the third rotational mode. We mean the first two modes, the classical modes that don't contribute to the specific heat of H2 at low temperature. It's a quantum mechanical effect. The reason there is no third rotational mode is strictly classical, and it's because when ...

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The number of degrees of freedom isn't $3N$, it's $3N$ minus the number of contraints. The $N=2$ is a special case since with two particles molecules can't help being linear. However for $N>2$ if the molecule is linear you are constraining the motion of the third particle because it can only move along the line joining the other two. Likewise for higher ...

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Does this mean that there are two different fields, one static field and one induced by a laser? Yes, that is exactly right. There is a static (meaning not time dependent) electric field $\vec{E}_\text{static}$ $(*)$ and there is also a time-varying electric field $\vec{E}_\text{laser}$ from the laser. Since we are told the laser field is linearly ...

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I have solved my problem with some careful head scratching and reading. It turns out I misread the paragraph after Eq. (2.9). This is NOT the integration formula, just a statement of the boundary condition value for P as R -> inf and U -> constant. It provides the first two values needed for the rest of the inwards integration. The correct formula to use ...

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