47 votes

Are there non-transparent gases?

First, a little bit of background. Transparency is not an absolute property of a material. Every substance is opaque, so long as light has to pass through enough of it, and opacity also changes ...
28 votes

Microwaving a glass of water, what happens?

Heating water on a hot plate is safe, because the hottest point is at the bottom of the pot. A lot of relatively small bubbles appear there without much overheating of the water, because there is a ...
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20 votes

Are there non-transparent gases?

I'd separate transparent and colorless. Most gases are transparent or very nearly so because the concentration is low and absorptions are often weak. Chlorine, though is yellow-green, and has a ...
17 votes
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Why is beryllium transparent to x-rays?

The amount of X-rays absorbed by an element depends on the size of its atoms (its absorption cross-section, specifically, as affected by the size of core orbitals that contain electrons that can be ...
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14 votes

Microwaving a glass of water, what happens?

The mode of heating of a water glass in a microwave and on a stove is actually very similar. While it's true that microwave radiation penetrates somewhat into the body of water, the penetration depth ...
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14 votes
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Can reactions produce microwave or radio wave radiation?

An ammonia maser qualifies as an inorganic RF-emitting reaction. As the nitrogen changes position in the $\ce{NH3}$ molecule, ~24 GHz radiation is emitted. Similarly, organic methanol, $\ce{CH3OH}$ ...
12 votes
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In spectroscopy, is it possible for the sample to be excited multiple times?

Very technically? Yes. Realistically? The probability is small enough that even if it does happen, the peaks for the multiple transitions are going to be small enough that we cannot really observe ...
11 votes
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Why does microwave heat up things so much more quickly than visible light?

Microwaves don't have more energy, they just resonate at the frequency that causes molecular bonds to rotate. This specifically applies to dielectric molecules, molecules like water that have electric ...
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11 votes

Is it safe to look at a mercury gas discharge tube?

Could it have caused irritation or injury? Possibly, but not likely, depending on a few factors: The intensity of the emitted ultraviolet. Proximity to the light source. Length of exposure. You'd ...
9 votes
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What chemical properties that allow for colour exist in the dark?

The chemical property that creates colour is the ability to absorb light of a specific visible wavelength. There is more than one way to do this. Mostly colour is caused by the existence of ...
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8 votes

Why does microwave heat up things so much more quickly than visible light?

The key difference with microwaves is the amount of energy emitted Microwaves don't have more "energy" than visible light per photon. But this is irrelevant in the case of a microwave oven. ...
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8 votes

Microwaving a glass of water, what happens?

A microwaved glass of water will 'bump' if the glassware is clean and the microwave heating is uniform. The water has some tensile strength, so a bubble will not form at the exact boiling ...
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8 votes
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Can gas be made to block radiation better?

Your question seems to be about the ozone layer, but shows some misunderstanding. First, ozone, $\ce{O3}$, absorbs some "radiation", specifically electromagnetic radiation, e.g. visible light or ...
8 votes
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A question regarding excitation of electrons in atomic orbital

The OP asked Is the dexcitation and remission of photon a phenomenon which can only be seen when an electron goes from one shell to another like from n=1 to n=2 or can it also be seen when electron ...
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7 votes
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Why does the photoelectric effect depend on the frequency of the light?

The photoelectric effect is described by the following equation $$E_\mathrm{max} = h\nu - \mathrm{WF_M}$$ where $E_\mathrm{max}$ is the maximum kinetic energy of the electron escaping from the ...
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7 votes
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Can visible light or infrared radiation excite electrons?

Different regions of the electromagnetic spectrum correspond to different atomic and molecular processes, each with one or more associated spectroscopies. Here is a general summary, with decreasing ...
6 votes
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Why can UV light initiate a reaction between hydrogen and chlorine gas?

Before going into the mechanism of this reaction, I suggest you look up free radical mechanism, as this reaction takes place through that. $\ce{Cl-Cl}$ bond in $\ce{Cl2}$ is weak enough to be broken ...
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6 votes
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What is the quantum mechanical explanation of X-ray diffraction?

The description given in your question pretty much explains things. I would put it in slightly different words which may or may not help, which is that the x-ray photon induces a dipole moment in the ...
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6 votes
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De-excitation of a molecule

After radiation is absorbed and the electron is at an excited state in the molecule there are several pathways for de-excitation to occur (see fig.). The pathway of choice depends on its rate, ie how ...
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5 votes

In spectroscopy, is it possible for the sample to be excited multiple times?

From memory something like this has been used as a basis for isotope separation using intense $\ce{CO2}$ lasers to fragment molecules. A process of 'ladder climbing' takes place aided by the fact that ...
  • 27.6k
5 votes
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Are photons ejected from atomic nuclei?

I have heard that electrons absorb or eject photons when transitioning from one orbital to another. Is this correct? Not exactly. The atom as a whole emits or absorbs the photon. There is no reason ...
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5 votes

Wavelengths of the visible spectrum

The comments on the question discuss this may not be about chemistry. One could argue that colors are chemistry related because they are associated with chemical substances: like minerals, chlorophyl, ...
5 votes

Can gamma radiation cause transmutation?

Yes. See Photo-Fission in Heavy Elements (1947) Phys. Rev. 71, pages 3-10 : fission should be possible for all heavy nuclei which lie well beyond the minimum of the packing fraction curve, ...
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5 votes
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Can gamma radiation cause transmutation?

Answer to a More General Form of Your Question The answer to the question Can gamma radiation make non-radioactive stuff radioactive? is yes, but only if the gamma ray has enough energy. "...
5 votes

Stability of Bohr Orbits

Not every model is perfect. Rutherford's model suffered from the problem of electromagnetic radiation but answered important questions about the structure of atoms by showing the existence of a ...
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5 votes

What is the quantum mechanical explanation of X-ray diffraction?

Explaining the diffraction of a photon off of a crystal lattice quantum mechanically is the same as finding what momenta can be transferred to the photon by the crystal lattice. The simplest way to ...
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5 votes

Can we make chemical bonds using light, instead of breaking them?

Surely, if light can break bonds, it can make bonds as well. We find some simple examples in high school textbooks as well, such as the chlorination of olefin compounds under the presence of UV light. ...
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5 votes

Can we make chemical bonds using light, instead of breaking them?

Is it possible to use a specific wavelength to get the atoms to bond again? Not directly. The crucial step in photochemistry is the absorption of a photon. Usually, this results in a molecule in an ...
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5 votes
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How does carbon dioxide in the atmosphere keep heat trapped?

$\ce{CO2}$, like all other matter, can only absorb photons of energies corresponding to some kind of quantum transition with a high transition probability, whether that is a rotational, vibrational, ...
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