Thursday, November 11, 2010

Question #18

18) What is the explanation for the discrete lines in atomic emission spectra?  How did this affect the model of the atom?

The discrete lines in the atomic emission spectra is from light emitted from the atoms transition back to the ground state from its excited state.  The atom gains this excited state when current flows through the atom and gains a brief potential energy.  Using an atom this light is split into different frequencies, or colors, of light in discrete lines.  This showed us that electrons must be in specific energy levels in the space of the atom.


  1. When light passes through a prism, the frequencies of light emitted by an element separate into discrete lines. When atoms absorb energy, electrons movie to higher energy levels. These electrons later lose energy by emitting light when they return to lower energy levels. Ordinary light is made up of a mixture of all the wavelengths of light. However, each specific frequency of visible light emitted corresponds to a particular color. Each element has a different atomic emission spectrum. Similarly to the idea that no two humans have the same fingerprints, no two elements have the same light emission spectrum. Just like fingerprints can be used to identify humans, atomic emission spectrums can be used to identify elements. Each discrete line corresponds to one exact frequency of light emitted by the atom.

  2. great job, nick, next time maybe mention the photoelectric effect

  3. Good job!
    I would comment on the photoelectric efect as already advised and discuss how photons interact with electrons in orbitals aroound an atom through the wave particle duality