ASTR 20 Lecture Notes - Lecture 22: Photon
Document Summary
Frequency: the number of crests that pass through a point each second (hz) Amplitude: half the difference in height between the crest and trough. All light travels at c= 300,000 km/s. Each photon has a wavelength and a frequency. The energy of a photon depends on its frequency. E= h x f; e=energy of photon, f= frequency, h= constant. The higher the photon energy, the shorter its wavelength. Atomic number= # of protons in nucleus. Atomic mass number= # of protons + neutrons. Isotope= same # of protons but different # of neutrons. Molecules: consist of two or more atoms. Mirror reflects light in a particular direction. Movie screen scatters light in all directions. There are three basic types of spectra. Can be used to tell us what things are made of. They can also tell us the temperatures of planets and stars. And they can tell us the speed of a distant object.
