CEM 141 - EXAM 2 QUESTIONS & ANSWERS
1. mole: 6.022 x 10^23 things
number of particles that allows us to convert from the molecular to the macroscopic level
2. limiting reactant/reagent: amount of one of the reactants which limits how much product can be
formed. smallest amount.
3. percent yield: actual/theoretical x 100
4. electromagnetic radiation:
5. wavelength: The distance between two corresponding parts of a wave. seconds/wave. 1/frequency. measured in
m
6. amplitude: Height of a wave
7. frequency: waves/second. 1/wavelength. measured in Hz
8. Constant (c): 3 x 10^8 m/s. c=(wavelength)(frequency)
1/
16
,9. constructive interference: The interference that occurs when two waves combine to make a wave with a
larger amplitude = brighter
10. destructive interference: The interference that occurs when two waves combine to make a wave with a
smaller amplitude = darker
11. diffraction: The bending of a wave as it moves around an obstacle or passes through a narrow opening
2/
16
, 12. models of light: light as a wave/particle
13. photoelectric effect: The emission of electrons from a metal when light shines on the metal.
14. why is light considered a wave (evidence): dittraction, interference
15. why we consider light a wave (claim, evidence, reasoning): claim-light is a wave
evidence- dittraction, interference
reasoning- light acts the same as waves as demonstrated in dittraction and interference.
16. why is light considered a particle: photoelectric ettect. there is a threshold frequency below which no
electrons are emitted from metal when light is shined . if light were a wave, the intensity should increase the energy and
eject electrons.
17. photon: Einstein postulated light must come in packets (particles or quanta)
18. e
nerg
y:
E=hv
h=6.62
6x10^-
3/
16
1. mole: 6.022 x 10^23 things
number of particles that allows us to convert from the molecular to the macroscopic level
2. limiting reactant/reagent: amount of one of the reactants which limits how much product can be
formed. smallest amount.
3. percent yield: actual/theoretical x 100
4. electromagnetic radiation:
5. wavelength: The distance between two corresponding parts of a wave. seconds/wave. 1/frequency. measured in
m
6. amplitude: Height of a wave
7. frequency: waves/second. 1/wavelength. measured in Hz
8. Constant (c): 3 x 10^8 m/s. c=(wavelength)(frequency)
1/
16
,9. constructive interference: The interference that occurs when two waves combine to make a wave with a
larger amplitude = brighter
10. destructive interference: The interference that occurs when two waves combine to make a wave with a
smaller amplitude = darker
11. diffraction: The bending of a wave as it moves around an obstacle or passes through a narrow opening
2/
16
, 12. models of light: light as a wave/particle
13. photoelectric effect: The emission of electrons from a metal when light shines on the metal.
14. why is light considered a wave (evidence): dittraction, interference
15. why we consider light a wave (claim, evidence, reasoning): claim-light is a wave
evidence- dittraction, interference
reasoning- light acts the same as waves as demonstrated in dittraction and interference.
16. why is light considered a particle: photoelectric ettect. there is a threshold frequency below which no
electrons are emitted from metal when light is shined . if light were a wave, the intensity should increase the energy and
eject electrons.
17. photon: Einstein postulated light must come in packets (particles or quanta)
18. e
nerg
y:
E=hv
h=6.62
6x10^-
3/
16
