1. A B C Which absorption spectrum belongs to the color of
the solution shown here? A B C

2. A B C Which absorption spectrum belongs to the color of
the solution shown here? A B C

3. How much visible light is transmitted through typical sunglasses?
70-80%
40-50%
10-30%
1-5%

4. How much visible light is transmitted through typical sunglasses?
70-80%
40-50%
10-30%
1-5%
Weber-Fechner Law: eye senses brightness roughly logarithmically
Optical Density OD = log10(I0/I)
I0 = intensity before absorber
I = intensity behind absorber
Typical sunglasses: OD  0.5-1

5. A B Consider the complex index of refraction of a gas n = n’ - i
where
Which graph belongs to the real part n’ ?
A B

6. A B Consider the complex index of refraction of a gas n = n’ - i
where
Which graph belongs to the real part n’ ?
A B