Wavelength, a(nm) 10310-110103105107109101110131015 Frequency, v(Hz) 10201018101610141012101010810610410 Gamma Ultra- Radio Type of radiation ray X-ray violet Infrared Microwave wave 400 Visible spectrum 700 High energy Low energy Electromagnetic spectrum Wavelength ()and frequency (v)are inversely related. Our eyes are sensitive to only a narrow range of wavelengths of radiation, the visible region, which extends from about 400 nm(violet)to about 700 nm(red). Short-wavelength(high-frequency) light has a high energy content; long wavelength(low-frequency) light has a low energy content Figure 3-4
Figure 3-4
One wavelength Figure 3-4-1 Longer wavelength 760 nm T and radio waves Red Zoo nm Micro- Infrared Color 6oo nm Visible spectrum of visible Yellow UV light X rays Green SOo nm BlL∈ Gamma rays Violet 400nm 38o nm Electromagnetic 人八八八 spectrum Shorter wavelength The electromagnetic spectrum aves in the electromagnetic spectrum have similar properties but different wavelengths and methods of production. Radio waves are the longest (and least energetic) waves, with wavelengths as long as 20 km. Gamma rays are the shortest (and most energetic) waves. visible light represents a small fraction of the electromagnetic spectrum and consists of a mixture of wavelengths ranging from approximately 38o to 76o nm. The energy from visible light is used in photosynthesis
Figure 3-4-1
100 80 Chlorophy‖b 8co 60 E苏 40 Chlorophyll a u20 400 500 600 700 Wavelength(nm) Figure 3-5
Figure 3-5
280 240 a-Caroten 200 160 anthony 1201 那8o 40 Fig 3-6 400420440460480500520 a/nm
Fig.3-6
E 2nd excited singlet state Heat E I st excited singlet state Triplet Heat Fig 3-7 E ground state
Fig. 3-7