1. Atomic Spectrum
March 25, 2013

2. Objectives
1.
2.
3.
Explain why scientists know the identity of
the chemical compositions of stars
Describe a flame test
Distinguish between absorption and
emission

3. 
Atoms can absorb and release energy

When atoms release energy they emit light

Each atom emits only a certain frequency
of light

4. Shell Model


Electrons can jump between shells when
excited
When they jump back down they release
that energy as light

5. Na
Li
B
Cu
Ca

6. Spectroscope

White light separates into its color
components by a prism

Each color corresponds to a different
frequency of electromagnetic radiation

8. Spectroscope

10. Spectroscope

Observe color components of any light
source

11. Atomic Spectrum

Light from atoms consist of a number of
discrete frequencies rather than a
continuous spectrum

Pattern of frequencies of a particular
element – atomic spectrum

13. 
Atomic spectrum – atoms “finger print”

Emission – the frequencies the gas emitts
Absorption – frequencies of all white light
EXCEPT those that are absorbed by the
gas


14. •
 Emission
 Absorption

15. 
http://jersey.uoregon.edu/vlab/elements/Elemen

16. 
http://video.google.com/videoplay?docid=25558