ch4 spectrum lab

Spectrum lab                          Name_________________pd_________

Discussion:  When heat , light or electrical energy is added to atoms, electrons go to higher energy levels.  When they return their original level, they give off that energy in characteristic colors.   If a spectroscope is used to separate different colors (wavelengths) of light,  distinctive bands of light can be seen.  These can  be used to identify the element.

Procedure:  Observe the different lights with the rainbow glasses (a crude spectroscope).  Record your results below, coloring later.  Use the knowns to identify the unknowns.

Name___________________ pd_____

I Bright line spectrum

spectrum    element

         _______________________________

    H  ________________________________

          R       O       Y       G       B       I       V  

        ________________________________ 

    He_________________________________

         R       O       Y       G       B       I      V

      _____________________________________  

 Hg ___________________________________

          R       O       Y       G       B       I       V  

       ________________________________ 

    Kr_________________________________

       R       O       Y       G       B       I       V   

     _______________________________

    N ________________________________

          R       O       Y       G       B       I       V  

       ________________________________ 

    Ne ________________________________

      other elements tbd:

       _______________________________ 

  u-1_________________________________

       R       O       Y       G       B       I       V   

     _______________________________

  u-2 ________________________________

          R       O       Y       G       B       I       V  

       ________________________________ 

  u-3_________________________________

       R       O       Y       G       B       I      V 

       ________________________________ 

  u-4_________________________________

       R       O       Y       G       B       I      V 

u-5 (a mixture of 2 of the first 4 unknowns

_________________________________

__________________________________

  R       O       Y       G       B       I      V  

II. Identify the elements by looking  at the spectrophotometer display (in class demonstration if time permits)  

Fill in your results from both flame and spectrum on this form.

class data available day assignment due

do these conclusion questions:

What is spectroscopy?  Why is it valuable in the study of stars? (internet)

Give the wavelengths, in nm,  of the different colors of visible light. use pg 98 text (p92 of etext)

R =              O =               Y=             G=             B=            I=               v=

Helium was discovered on the sun before it was discovered on earth.  How is that possible?  Where does the word ‘helium’ come from?   Where does the helium we use come from?  What country has the lion’s share of this resource? (use internet)