whats photon in chemistry?
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A photon is a unit of energy.  It is often found when an electron drops from an excited orbital back down to a lower-energy orbit.
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The energy of a photon is proportional to its frequency, the constant of proportionality being called Planck's constant who discovered this relation.\n\nE = h * Frequency\n\nIf you know the frequency (or wavelength) of the light you can calculate the corresponding energy.\n\nWhen an electron jumps from an excited state back to its ground state it will emit energy.  If the frequency is in the right range we will see that as light.
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A pattern of dark lines or bands superimposed on a continuous spectrum. When a continuous spectrum of radiation (a broad range of wavelengths) passes through a material medium (for example, a cool, low-pressure gas), selective absorption occurs at certain particular wavelengths. This gives rise to a series of dips in intensity (absorption lines) which, in the visible region of the spectrum, appear as dark lines against the bright background of the ‘rainbow’ band of colors that comprises the continuous spectrum. Photons of electromagnetic radiation may be absorbed through radiative excitation, a process that occurs when an electron in one of the lower energy levels of an atom or ion absorbs a photon with energy precisely equal to the difference in energy between that level and one of the higher permitted levels and, as a result, jumps (makes an ‘upward transition’) from the lower to the higher level. Because the energy of a photon is inversely proportional to wavelength, the larger the energy gap, the shorter the wavelength of the radiation that is absorbed when an electron makes a particular transition. An electron does not normally remain in an excited level for long (typically 10−8 s). When it drops down again, it emits a photon or photons that may or may not have the same wavelength as the one that was originally absorbed (depending on whether it drops directly to its original level or descends in a series of smaller steps). If it drops in a series of steps, each of which corresponds to the emission of a photon of lower energy (and longer wavelength) than the one thatwasoriginally absorbed, the total number of photons of the original energy will be reduced and the spectrum will be depleted at the input wavelength. Furthermore, although all the input photons were traveling along essentially the same direction (from the source to the observer), the re-emitted photons travel away in random directions. Consequently, far fewer photons at the absorption wavelength reach the observer than photons of other wavelengths. The resulting absorption line is darker than the adjacent part of the continuous spectrum but, because some photons of that wavelength do reach the observer, not totally black.\nBecause each permitted transition corresponds to absorbing light of one particular wavelength, atoms or ions of a particular element produce absorption lines at a number of different wavelengths, each chemical element having its own distinctive ‘fingerprint’ pattern of absorption lines. The shortest-wavelength lines correspond to the largest energy gaps (i.e. to transitions from the lowest, or ‘ground’, level of the atom or ion). If an electron absorbs a photon with energy in excess of the ionization energy (or ‘ionization potential’), it will be removed from the atom. The absorption spectrum of a particular species of atom consists of several series of lines, corresponding to the various permitted transitions, the short-wavelength limit of the series corresponding to the photon energies above which ionization takes place. Because ionizing photons can, in principle, have any value of energy above the ionization energy, absorption can take place over a continuous range of wavelengths, shorter than the series limit. Absorption of this kind is called an absorption continuum. The prominence (‘strength’) of any particular line depends on the number of atoms of the appropriate chemical element that have electrons residing in the energy level from which the relevant upward transition takes place (the degree of excitation). That, in turn, depends on the abundance of the particular chemical element (the relative proportion of that element in the absorbing substance) and on a number of other factors, in particular the temperature (the higher the temperature, the greater the proportion of electrons in excited states).\nIn addition to producing absorption through electronic transitions (like atoms and ions), molecules may also a
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Light is a particle. Wave is its function.
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photon is a massless particle that is the rest mass of photon is zero which means all the mass of a photon is due to relativistic speed.\nhowever, it has been proved by Davison and Germer experiment that whenever a subatomic particle moves with a velocity approaching the speed of light a wavelength is associated with it.which is originally on the concept of De Broglie\nmathematically\nlemda=h/mv\nAs per ur question we can say photons moves with speed of light but we cannt say photon a substance unless we make to stop it and it converts to positron and electron(pair production)
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The energy of the incoming photons is given by Planck's relationship:  energy = Planck's constant * frequency.\n\nYou are given the wavelength, not the frequency, so you need to know that for any wave, the wavespeed = frequency * wavelength, so frequency = wavespeed/wavelength.  For photons, wavespeed = c.\n\nh = 6.626068 × 10^-34 34 m^2 kg / s (Planck's constant)\nc = 2.998 × 10^8 m / s (speed of light)\nwavelength = 48.2 x 10^-9 m (given in problem)\n\nPutting this together, the energy of each incoming photon is:\n\nE_photon = h*c/(48.2 x 10^-9 m) = 4.121 x 10^-18 J\n\nThe outgoing electron has kinetic energy = 1/2 * m * v^2.  You are given both m and v:\n\nE_electron = 1/2 * 9.109 x 10^-31 kg * (2.371 x 10^6 m/s)^2 \nE_electron = 2.56 x 10^-18 J\n\nThe ionization energy is the difference in energy between the incoming photon and the kinetic energy of the outgoing electron.  Because the question asks for the energy in joules per mole, we must multiply the energy difference for a single photon/electron pair by Avagadro's number:\n\nE_ionization = (E_photon - E_electron)* N_A\n\nE_ionization = (4.121 x 10^-18 J -2.56 x 10^-18 J)*6.022 x 10^23 mol^-1\n\nE_ionization = 9.4 x 10^5 J/mol = 940 kJ/mol
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The UV-VIS spectrum is due to the electronic transitions of the molecule. This is characteristic of a compound. Qualitative and quantitative estimations of compounds are possible by this non destructive technique. \n\nThe absorption (A) of a solution at a particular wavelength is given by Beer-Lambert's law ect = A where c is the concentration of the compound , t is the thickness of the cell and e is the molar extinction coefficient characteristic of the compound at a given wavelength. This principle is used for quantitative measurements. \n\nCary 5E is a high resolution spectrophotometer to study the electronic spectrum of solutions, single crystals and powder samples (in nujol mull) in the range of 3150-185 nm. This is a double beam instrument controlled by a microprocessor. Base line correction, repetitive scan, kinetics, derivative and concentration modes are possible. Diffuse reflectance is available for solid samples. VT accessory in the range 5-90 degrees Centigrade is available\n\nThis principle is used for quantitative measurements.
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The light you see comes from photons emitted when an electron drops from a higher-energy orbit to a lower-energy one.  Quantum mechanics requires that the length of the orbit be an integral multiple of the wavelength of the electron's wavefunction.  That means these orbit energy levels are discrete, and so the energy difference between the levels has a very specific value, and the photon emitted must have exactly that energy and therefore that frequency.  Different elements will have different possible orbital energy levels, and therefore different emission spectra.
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I would also say the answer is photon.
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A solution could absorb energy from photons, but they are a measurement of light. Rather than being absorbed, for example, the solar radiation breaks down chemicals in the leaves of plants which allows the plants to form food. Rather than being absorbed, the energy causes a change, such as increased temperature and chemical reaction.
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Photons.\n\nI've heard of wavicles, but I think that sounds like a frozen dessert.
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Water.\n\nWater donates an electron to the P680 molecule of photosystem II to replace the electron that is lost when a photon of light strikes it.
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indeed light is as said before photons although according to quantum physics everything in the universe is made from molecules, molecules are made from protons neutrons and electrons and those are made from quanta's.But quanta's are in fact (in a way at least)compressed energy. So you can't really say that they are made from something different technically speaking at least
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Light isn't even physical, it is a form of energy made up of sub-atomic particles called Photons. Photons aren't even a form of matter, so it wouldn't be solid, liquid, gas, plasma, or any other kind of Phase (those are the only 4 known phases). Good examples of Gasses at normal room temperature would be Nitrogen, Hydrogen. Oxygen, Carbon Dioxide, and Methane.
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sun light - the photons break the covalent bonds between the hydrogen and oxygen
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Violet is the highest energy visible light.  Above that is ultraviolet, X-rays, and gamma rays.
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Photons are EM waves. They have the same speed.