PH 122 Lecture Notes - Ionizing Radiation, Atomic Number, Emission Spectrum
Document Summary
Far red end of the spectrum, 750 nm. Far blue end of the spectrum, 400 nm. Peak intensity shifts to shorter wavelengths as the temperature increases. Wien"s law for the peak wavelength of a thermal emission spectrum. A typical incandescent lamp has a filament at a temperature of approximately 2500 c. Temp in k = 2500 + 273 = 2773 k. The three different types of cones have different color sensitivities. The band gap of the silicon used to make the ccd detector in a black and white security camera is 1. 12 ev. Photons with energy greater than this will be detected. N. b. e = 0. 97 for skin of any color. A typical human has a surface area of about 1. 8 m2. All skin, regardless of color, has an emissivity of about e = 0. 97. How much power does a person"s body radiate at normal skin temperature? (about 33 c, or 306 k) Shorter than 300 nm can damage dna.
