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EMISSION SPECTRUM. When Matter is heated it gives off light Example: light bulb The electrical energy absorbed by the filament excites the atoms ’ electrons The absorbed energy is eventually released in the form of light. CONTINUOUS (WHITE LIGHT) SPECTRA
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When Matter is heated it gives off light • Example: light bulb • The electrical energy absorbed by the filament excites the atoms’ electrons • The absorbed energy is eventually released in the form of light
CONTINUOUS (WHITE LIGHT) SPECTRA When normal white light (such as light from the sun or a light bulb) is passed through a prism, the light separates into a continuous spectrum of colors
PRISM • White light is broken into 7 spectral lights, what are they? ROY G BIV
Originally Scientists (even Newton) thought that light was made up of particles but this couldn’t’ explain why different color were refracted differentNOTICE: Voliet bends a lot more than Red
Transverse vs Longitudinal Waves Transverse Longitudinal
Wavelength vs. Frequency • WAVELENGTH = distance light travels to complete 1 cycle • FREQUENCY = number of cycles completed in 1 second
The colors we see have different wave lengths • Red = longer wave length • Violet = shorter wave length ,lower frequency ,higher frequency Which one has the higher frequency? Wavelength and Frequency have an inverse relationship
You can even calc. the Wave Velocity • speed of wave in direction is traveling • Velocity = wavelength x frequency Velocity =
Scientists realized that many light waves couldn’t been seen with the naked Electromagnetic Spectrum
Lower Energy Higher Energy LINK
THE MYSTERY OF EMISSION- LINE SPECTRUM Solids, liquids, and dense gases emit light of all wavelengths, without any gaps = Continuous Spectrum
Thin gases emit light of only a few wavelengths = Emissions or Bright Line Spectrum
Bright Line Spectrum • Atoms cannot emit energy continuously, rather they emit energy in precise quantities • How does this work • Electrons absorb energy (EXCITED) and “jump” to a higher energy level • After a short time, they “fall” back to lower energy level, giving off a specific amount of energy (a quantum of energy) in the form of a photon (light)
Scientists of the 19th century quickly figured out that each element generates its own unique set of wavelengths of emissions and absorptions. Hydrogen: