Photons, of electromagnetic radiation

In the third mechanism excess energy is released as a photon of electromagnetic radiation. 

Arrange the following types of photons of electromagnetic radiation in order of increasing energy -y-rays, visible light, ultraviolet radiation, microwaves, x-rays. 

The gamma ray is a photon of electromagnetic radiation with a very short wavelength and high energy. It is emitted from an unstable atomic nucleus and has high penetrating power. 

The absorption of a photon of electromagnetic radiation corresponding to a transition from a ground electronic state to a more energetic electronic state, followed by a release of electromagnetic energy as the molecule returns to a lower electronic state, is called photoluminescence. If the emission of... 

The energy of a photon of electromagnetic radiation is given by Planck s equation ... 

A few radioisotopes of biochemical significance are y emitters. Emission of a y ray (a photon of electromagnetic radiation) is often a secondary process occurring after the initial decay by /3 emission. The disintegration of the isotope 131I is an example of this multistep process. 

The velocity of an electron that is emitted from a metallic surface by a photon of electromagnetic radiation is 2.2 X 103 km-s . (a) What is the wavelength of the electron (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 1.00 X 1015 s. How much energy is required to remove the electron from the metal surface (c) What was the wavelength of the photon that caused the electron moving at 2.2 X 103 km-s 1 to be ejected from the metal ... 

Both elastic and inelastic scattering can be understood in terms of energy transfer between photons and molecules as illustrated in Figure 9.6. As mentioned before, photons of electromagnetic radiation can excite molecular vibration to a higher level when vph = vvit,. If the excited vibration returns to its initial level (Figure 9.6a), there is no net energy transfer from photons to molecular vibration. Thus, the scattered photons from molecules will have the same frequency as the incident radiation, similar to elastic collisions between photons and molecules. If the... 

Gamma rays are high-energy photons of electromagnetic radiation they are normally not considered to be particles. When a nucleus produces only gamma radiation, the atomic number and mass number remain the same. 

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