This document discusses atomic spectra and how they can be used to identify elements. It explains that atoms emit and absorb light at specific frequencies when electrons jump between energy levels, and that each element has a unique atomic spectrum. A spectroscope can be used to separate light into its component frequencies, allowing scientists to determine the chemical composition of stars and perform flame tests by observing the atomic spectra emitted or absorbed.

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