1. A spectrophotometer measures

• 1. light given off by a substance
  2.light changed (change in wavelength) by a substance
  3.light that passes through a substance
  4.light that is fluoresced by a substance

2. Ultraviolet light
1. has a short wavelength
2.is measured at 185 to 300 nm
3.is harmful to human eyes
4.all of the above

3. Beer's law states that the absorbance equals
(extinction coefficient)*(light path)*(concentration)
1.2 - log % Transmission
2.natural log of the concentration times the light path length
3.(extinction coefficient)*(light path)*(concentration) and 2 - log % Transmission 
4.(extinction coefficient)*(light path)*(concentration) and natural log of the concentration times the light path length 

4. % Transmission = %T = 100*(I/Io), where Io equals
1.light reaching the photocell
2. light striking the cuvette
3. 1% of the incidence light

5. Select the single best answer.  The blank for a spectrophotometer should be composed of
1. water
2.uninoculated medium
3.empty cuvette
4.liquid as defined in the experiment protocol

6. The purpose of a blank is
1.to cancel readings due to the color of the reagents
2.to account for imperfections in the cuvette
3.to account for imperfections in the cuvette and to cancel readings due to the absorbance of the reagents