Electromagnetic radiation Energy that

Electromagnetic radiation Energy that is propagated by means of electric and magnetic fields that oscillate in directions perpendicular to the direction of travel of the energy. 

Radiant energy or electromagnetic radiation Energy that can be described in terms of either oscillating electric and magnetic fields or in terms of a stream of tiny packets of energy with no mass. 

Gamma rays (y rays), which are high-energy, short wavelength, electromagnetic radiation particles that originate from within the nucleus... 

All spectra are due to the absorbance of electromagnetic radiation energy by a sample. Except for thermal (kinetic) energy, all other energy states of matter are quantized. Quantized transitions imply precise energy levels that would give rise to line spectra with virtually no line-width. Most spectral peaks have a definite width that can be explained in several ways. First, the spectral line-width can be related to the... 

The reaction sequence shown above illustrates three important aspects of chemistry that will be shown to be very important in the discussion of atmospheric chemistry in Section 2.8. The first of these is that a reaction may be initiated by a photochemical process in which a photon of light (electromagnetic radiation) energy produces a reactive species, in this case the Cl- atom. The second point illustrated is the high chemical reactivity of free radical species with unpaired electrons and incomplete octets of valence electrons. The third point illustrated is that of chain reactions, which can multiply manyfold the effects of a single reaction-initiating event, such as the photochemical dissociation of Cl2. 

Particle properties of electromagnetic radiation Behavior that is consistent with radiation acting as small particles or quanta of energy. 

Momentum is mass times velocity, mv. Because electrons are so small and move so rapidly, their motion is usually detected by electromagnetic radiation. Photons that interact with electrons have about the same energies as the electrons. Consequently the interaction of a photon with an electron severely disturbs the motion of the electron. It is not possible to determine simultaneously both the position and the velocity of an electron, so we resort to a statistical approach and speak of the probability of finding an electron within specified regions in space. 

Nonionizing electromagnetic radiation (NIER) That portion of the electromagnetic spectrum below about 10 Hz, characterized by waves of insufficient quantum energy to break electrons free from atoms. 

As seen in the previous two chapters, spectroscopy allows us to probe molecular structure by studying the interaction between matter and electromagnetic radiation. Recall that the frequency of light determines the energy of a photon, and the range of all possible frequencies is known... 

If the zero-field splitting is larger than the microwave frequency in such cases as dd and drr excited states of transition metal complexes (vide supra), microwave resonance method cannot be applied. For example, if the separation among sub-levels is of the order of 10 to 100 cm", it is practically impossible to find electromagnetic radiation sources that can continuously cover such an energy region. In this case, one can obtain the sublevel properties indirectly by observing the temperature dependence of the lifetime and of the intensity of the luminescence. 

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