Color of chemicals

All chemical compounds have colors, and in some cases these are distinctive or useful for identification. The study of chemical structure by means of energy adsorption and release is generally referred to as spectroscopy. All atoms and molecules are capable of absorbing and releasing energy in the form of photons, accompanied by a change of quantum state. The amount of energy absorbed or released is the difference between the energies of the two ... more

All chemical compounds have colors, and in some cases these are distinctive or useful for identification. The study of chemical structure by means of energy adsorption and release is generally referred to as spectroscopy. All atoms and molecules are capable of absorbing and releasing energy in the form of photons, accompanied by a change of quantum state. The amount of energy absorbed or released is the difference between the energies of the two quantum states. There are various types of quantum state, including for example the rotational and vibrational states of a molecule. However the release of energy visible to the human eye, commonly referred to as visible light, spans the wavelengths approximately 380 nm to 760 nm, depending on the individual, and photons in this range usually accompany a change in atomic or molecular orbital quantum state. The perception of light is governed by three types of color receptors in the eye, which are sensitive to different ranges of wavelength... less