Infrared radiation, electromagnetic frequencies

Infrared radiation, electromagnetic spectrum and, 419, 422 energy of. 422 frequencies of, 422 wavelengths of, 422 Infrared spectroscopy, 422-431 acid anhydrides, 822-823 acid chlorides, 822-823 alcohols. 428, 632-633 aldehydes, 428. 730-731 alkanes, 426-427 alkenes, 427 alkynes, 427 amides. 822-823 amines, 428, 952 ammonium salts, 952-953 aromatic compound, 427-428, 534 bond stretching in, 422... 

In absorption spectroscopy a beam of electromagnetic radiation passes through a sample. Much of the radiation is transmitted without a loss in intensity. At selected frequencies, however, the radiation s intensity is attenuated. This process of attenuation is called absorption. Two general requirements must be met if an analyte is to absorb electromagnetic radiation. The first requirement is that there must be a mechanism by which the radiation s electric field or magnetic field interacts with the analyte. For ultraviolet and visible radiation, this interaction involves the electronic energy of valence electrons. A chemical bond s vibrational energy is altered by the absorbance of infrared radiation. A more detailed treatment of this interaction, and its importance in deter-... 

Radiation Resistance. Polysulfones exhibit resistance to many electromagnetic frequencies of practical significance, including microwave, visible, and infrared. Especially notable is the excellent resistance to microwave radiation, which has contributed to the excellent fit of polysulfones in cookware appHcations. Polysulfone also shows good resistance to x-rays, electron beam (24), and gamma (25,26) radiation under many practical appHcation conditions. 

The vibrational motions of the chemically bound constituents of matter have fre-quencies in the infrared regime. The oscillations induced by certain vibrational modes provide a means for matter to couple with an impinging beam of infrared electromagnetic radiation and to exchange energy with it when the frequencies are in resonance. In the infrared experiment, the intensity of a beam of infrared radiation is measured before (Iq) and after (7) it interacts with the sample as a function of light frequency, w[. A plot of I/Iq versus frequency is the infrared spectrum. The identities, surrounding environments, and concentrations of the chemical bonds that are present can be determined. 

Arrange the following types of photons of electromagnetic radiation in order of increasing frequency visible light, radio waves, ultraviolet radiation, infrared radiation. 

Infrared radiation is electromagnetic radiation lying at longer wavelengths (lower frequencies) than red light a typical wavelength is about 1000 nm. A wavelength of 1000 nm corresponds to a frequency of about 3 X 1014 Hz, which is comparable to the frequency at which molecules vibrate. Therefore, molecules can absorb infrared radiation and become vibrationally excited. 

In the electromagnetic spectrum, microwave radiation occurs in an area of transition between infrared radiation and radiofrequency waves, as shown in Fig. 1.1. The wavelengths are between 1 cm and 1 m and frequencies between 30 GHz and 300 MHz. 

Consider the following statements about electromagnetic radiation and determine whether they are true or false. If they are false, state why they are false, (a) Photons of ultraviolet radiation have less energy than photons of infrared radiation, (b) The kinetic energy of an electron ejected from a metal surface when the metal is irradiated with ultraviolet radiation is independent of the frequency of the... 

The first two of these methods (NMR and IR) are spectroscopic techniques in which the molecule is interrogated with electromagnetic radiation in a particular range of frequencies (NMR uses radio frequencies and IR spectroscopy uses infrared radiation). Only certain frequencies will be absorbed by a particular compound, and those frequencies that are absorbed can be used to infer structural details about the compound. 

Infrared radiation, like any electromagnetic radiation, is characterized by properties of frequency (v) and wavelengdi (X) that are related by the speed of light c ... 

Microwaves are electromagnetic radiation placed between infrared radiation and radio frequencies, with wavelengths of 1 mm to 1 m, which corresponds to the frequencies of 300 GHz to 300 MHz, respectively. The extensive application of microwaves in the field of telecommunications means that only specially assigned frequencies are allowed to be allocated for industrial, scientific or medical applications (e.g., most of wavelength of the range between 1 and 25 cm is used for mobile phones, radar and radio-line transmissions). Currently, in order not to cause interference with telecommunication devices, household and industrial microwave ovens (applicators) are operated at either 12.2 cm (2.45 GHz) or 32.7 cm (915 MHz). However, some other frequencies are also available for heating [1]. Most common domestic microwave ovens utilize the frequency of 2.45 GHz, and this may be a reason that all commercially available microwave reactors for chemical use operate at the same frequency. 

Electromagnetic radiation with a frequency of 0.3-300 GHz (X = 1-0.001 m) is called microwave radiation. The microwave part of the electromagnetic spectrum lies between the more energetic infrared radiation... 

Radio waves (also electromagnetic radiation) are characterized by frequencies given in kilohertz or megahertz (as on radio tuners). Infrared radiation... 

The speed of operation is interlinked with the properties of electromagnetic radiation at the corresponding frequencies. The frequencies of operation in modem IT devices have reached some GHz in the region of microwave radiation. A further increase would step to infrared radiation, visible light and so on see Fig. 1. 

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