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We see an object coloured because of the component of light reflected by it. But what is in the object that makes other wavelengths absorbed by it and one to reflect.
The atomic composition. Gold, for example, is all one kind of atom and so has a single characteristic wavelength that is emitted by the excitation caused by impinging photons. The impinging photons have various levels of energy and when they are strong enough, they cause the electrons in the gold atoms to jump up one energy state and when they drop back they produce one "gold" photon that then impinges on our inner eyes and our brain interprets it as what we call "gold". The energy not so used by the photons hitting the gold goes into making the bar of gold slightly hotter.shayan haider said:We see an object coloured because of the component of light reflected by it. But what is in the object that makes other wavelengths absorbed by it and one to reflect.
In a dense medium like a metal, the electrons do not "jump up an energy state". There is a continuum of energy levels (an energy band) and transitions of all values between limits can have any value. It is important to recognise that the H Atom model is not enough to deal with solid state situations. The reflection will be coloured slightly because of the details of the metal structure where certain frequencies may lose a different amount of energy in the reflection process.phinds said:The atomic composition. Gold, for example, is all one kind of atom and so has a single characteristic wavelength that is emitted by the excitation caused by impinging photons. The impinging photons have various levels of energy and when they are strong enough, they cause the electrons in the gold atoms to jump up one energy state and when they drop back they produce one "gold" photon that then impinges on our inner eyes and our brain interprets it as what we call "gold". The energy not so used by the photons hitting the gold goes into making the bar of gold slightly hotter.
Interesting. Thanks for that correction.sophiecentaur said:In a dense medium like a metal, the electrons do not "jump up an energy state". There is a continuum of energy levels (an energy band) and transitions of all values between limits can have any value. It is important to recognise that the H Atom model is not enough to deal with solid state situations. The reflection will be coloured slightly because of the details of the metal structure where certain frequencies may lose a different amount of energy in the reflection process.
This only applies in the case of gases. In dense media, there is a continuum of energy states within 'bands', rather than isolated levels. Often, within a wide band of energies, the light (other EM wavelengths also ) can be absorbed and give the surface 'colour'. You never get monochromatic light with pigments and dyes.jerromyjon said:A basic example is green plants, the chlorophyll in the leaves absorbs the red and blue for energy and the green is reflected.
I googled and found this: https://www.itp.uni-hannover.de/~zawischa/ITP/origins.html
Haven't gone though that page yet, but I'm pretty sure it has to do with the surface texture for the simple case of reflection, various atoms also absorb distinct narrow bands as the energy per photon has to be exactly right to bump an electron n shells further from the nucleus (like phinds said), and just the first few seconds of scanning that webpage shows it can get a lot more complicated than just simple "this makes it red, this makes it green, this makes it blue"
Thank you. You have given a very good and logical explanation. Thanks again for the answer.sophiecentaur said:In a dense medium like a metal, the electrons do not "jump up an energy state". There is a continuum of energy levels (an energy band) and transitions of all values between limits can have any value. It is important to recognise that the H Atom model is not enough to deal with solid state situations. The reflection will be coloured slightly because of the details of the metal structure where certain frequencies may lose a different amount of energy in the reflection process.
I was debating on the gas chromatograph approach with colored flames, etc. or the organochemical basis which really seems simple from what I'm reading... I'm into the energy diffusion widening the spectral bands (like you were heading it seems) related to the freedom of electrons transiting the double bonds in molecules.sophiecentaur said:This only applies in the case of gases
It means that it depends on the type of atoms but what about that lizard which changes its colour.sophiecentaur said:In a dense medium like a metal, the electrons do not "jump up an energy state". There is a continuum of energy levels (an energy band) and transitions of all values between limits can have any value. It is important to recognise that the H Atom model is not enough to deal with solid state situations. The reflection will be coloured slightly because of the details of the metal structure where certain frequencies may lose a different amount of energy in the reflection process.
I put it down to the Paui Exclusion Principle, basically. Nearby atoms cannot have the same states so they mutually widen the lines into bands.jerromyjon said:I was debating on the gas chromatograph approach with colored flames, etc. or the organochemical basis which really seems simple from what I'm reading... I'm into the energy diffusion widening the spectral bands (like you were heading it seems) related to the freedom of electrons transiting the double bonds in molecules.
Lizards (chamaeleons?) and several fish / octopi, have tiny sacs of different pigment that they can squeeze and control which pigment is closest to the surface. It works like Pointilistic Painting and an inkjet printer. No actual 'chemistry' involved to vary the colour.shayan haider said:It means that it depends on the type of atoms but what about that lizard which changes its colour.
Objects reflect specific colors because they absorb certain wavelengths of light and reflect others. The color that is reflected is the color that our eyes perceive. For example, a red object reflects red light and absorbs all other colors.
The color of an object affects its reflection because different colors have different wavelengths of light. Objects that are of a certain color will absorb all other colors except for the color that they reflect. This is why objects appear to be a certain color to our eyes.
Yes, the color of an object can definitely change the way it reflects light. This is because different colors have different wavelengths of light, and different wavelengths can be absorbed or reflected by different objects. This is why objects appear to be different colors under different lighting conditions.
No, the color of an object is not the only factor that affects its reflection. The texture, material, and surface of an object can also affect how it reflects light. Smooth and shiny surfaces tend to reflect more light, while rough and matte surfaces tend to absorb more light.
Objects appear to be different colors under different lighting conditions because the light source and the quality of light can affect the color of an object. For example, natural sunlight has a different quality of light compared to artificial lighting, which can cause objects to appear differently in each type of lighting.