Atomic Radiation It is now "known"that when an electron is in an excited state",it spontaneously decays to a ower-energy stable state. The difference in energy,AE,is given by: E5>E4>E3>E2>E One example could be: AE E5-E1=hv=Ephoton Energy Electron Energy Electron h=Planck's constant=6.6x10-34 [J s] in excited in lowest v=frequency of light [hz] state state (higher PE) (lower PE) The energy of the light is DIRECTLY PROPORTIONAL to the frequency,v. n=5 n=5 n=4 E4 Recall that the frequency,v,is related to n=4 the wavelength by: n=3 n=3 c=V入 (V=c/) n=2 E2 n=2 E, So,higher frequency higher energy n=1 n-1 →lower wavelength Before After This is why UV radiation browns your skin but visible light does not PDF文件使用"pdfFactory'”试用版本创建w,fineprint.cnAtomic Radiation The difference in energy, DE, is given by: DE = E5 – E1 = hn = Ephoton h = Planck’s constant = 6.6x10-34 [J s] n = frequency of light [hz] The energy of the light is DIRECTLY PROPORTIONAL to the frequency, n. Recall that the frequency, n, is related to the wavelength by: c = n l (n = c / l) So, higher frequency è higher energy è lower wavelength This is why UV radiation browns your skin but visible light does not ! It is now “known” that when an electron is in an “ excited state” ,it spontaneously decays to a lower-energy stable state. Before n = 1 n = 2 n = 3 n = 4 n = 5 Energy Electron in excited state (higher PE) E5 E4 E2 E3 E1 E5 > E4 > E3 > E2 > E1 After n = 1 n = 2 n = 3 n = 4 n = 5 Energy Electron in lowest state (lower PE) E5 E4 E2 E3 E1 One example could be: PDF 文件使用 "pdfFactory" 试用版本创建 ÿÿwww.fineprint.cn