MSU CEM 141 FINAL EXAM QUESTIONS AND
ANSWERS 100% Guarantee Pass
1. scientific question
Answer: can be answered by doing experiments, making observation, taking measurements, etc. in a
replicable way
2. Lights acts as what?
Answer: Particle and wave.
3. scientific model
Answer: drawing, graph, diagram, equation. represent many chemical entities.
4. Wavelength
Answer: The distance (m) of waves from peak to peak. Short x-ray (red), long: infrared (blue) Short -
higher energy
Long - lower energy
5. scientific theory
Answer: A well tested concept that explains a wide range of observations (explains why). changes with time.
Explains the underlying cause of a range of phenomena
6. Frequency (V)
, Answer: The number of wavefronts per second. Highest x-ray
7. scientific law
Answer: A theory that has been tested by and is consistent with generations of data. a rule that describes a pattern
in nature (explains what)
8. Velocity of Light
Answer: C = 3.00 X 10^8
= wavelength X frequency
9. scientific explanation
Answer: claim, evidence, reasoning
10. Amplitude
Answer: The intensity, height of peaks of waves. Highest blue light
11. size of an atom
Answer: 0.1 x 10^-9m
12. Energy of Wave ( J)
Answer: Increases as frequency increases and as wavelength decreases. Highest x-ray
13. Greek philosophers atomic theory
Answer: -first atomic theory
-elements
,Answer: earth, fire, water, air
-constantly in motion
-made of mostly empty space
14. Range of Wavelengths
Answer: 10^-16 - 10^8 = 24. Only a third are visible
15. Black Body Radiation
Answer: When a mass is heated it emits a type of EM radiation, at very high temps the mass becomes "white
hot" because all wavelengths of visible light become equally intense
16. molecular structure of a substance determines
Answer: the observable properties
17. atom
Answer: smallest distinguishable part of an element
18. Photoelectric Effect
Answer: Metals emit electrons when electromagnetic radiation shines on the surface, light is transfers energy
to the electrons at the metal's surface where it's transformed into KE that gives the electrons enough energy to leave
the atom
Depends on frequency not intensity
19. how many atoms are naturally occurring?
, Answer: 91 naturally occurring elements
20. How many electrons are emitted if the light is below it's threshold frequency
no matter the intensity?
Answer: None.
21. Dalton's atomic theory (1800s)
Answer: -elements composed of small, indivisible, indestructible, particles (atoms)
-all atoms of each element are identical (mass/properties)
-no subatomic particles
-compounds are formed by combos of atoms from 2+ elements
-chemical reactions occur from rearrangement of atoms
22. What increases the number of electrons to be emitted by the photoelectric
effect?
Answer: Intensity.
23. JJ Thomson
Answer: -first person to provide evidence of electron
-cathode ray tube
-plum pudding model
-particles carried electric charge
ANSWERS 100% Guarantee Pass
1. scientific question
Answer: can be answered by doing experiments, making observation, taking measurements, etc. in a
replicable way
2. Lights acts as what?
Answer: Particle and wave.
3. scientific model
Answer: drawing, graph, diagram, equation. represent many chemical entities.
4. Wavelength
Answer: The distance (m) of waves from peak to peak. Short x-ray (red), long: infrared (blue) Short -
higher energy
Long - lower energy
5. scientific theory
Answer: A well tested concept that explains a wide range of observations (explains why). changes with time.
Explains the underlying cause of a range of phenomena
6. Frequency (V)
, Answer: The number of wavefronts per second. Highest x-ray
7. scientific law
Answer: A theory that has been tested by and is consistent with generations of data. a rule that describes a pattern
in nature (explains what)
8. Velocity of Light
Answer: C = 3.00 X 10^8
= wavelength X frequency
9. scientific explanation
Answer: claim, evidence, reasoning
10. Amplitude
Answer: The intensity, height of peaks of waves. Highest blue light
11. size of an atom
Answer: 0.1 x 10^-9m
12. Energy of Wave ( J)
Answer: Increases as frequency increases and as wavelength decreases. Highest x-ray
13. Greek philosophers atomic theory
Answer: -first atomic theory
-elements
,Answer: earth, fire, water, air
-constantly in motion
-made of mostly empty space
14. Range of Wavelengths
Answer: 10^-16 - 10^8 = 24. Only a third are visible
15. Black Body Radiation
Answer: When a mass is heated it emits a type of EM radiation, at very high temps the mass becomes "white
hot" because all wavelengths of visible light become equally intense
16. molecular structure of a substance determines
Answer: the observable properties
17. atom
Answer: smallest distinguishable part of an element
18. Photoelectric Effect
Answer: Metals emit electrons when electromagnetic radiation shines on the surface, light is transfers energy
to the electrons at the metal's surface where it's transformed into KE that gives the electrons enough energy to leave
the atom
Depends on frequency not intensity
19. how many atoms are naturally occurring?
, Answer: 91 naturally occurring elements
20. How many electrons are emitted if the light is below it's threshold frequency
no matter the intensity?
Answer: None.
21. Dalton's atomic theory (1800s)
Answer: -elements composed of small, indivisible, indestructible, particles (atoms)
-all atoms of each element are identical (mass/properties)
-no subatomic particles
-compounds are formed by combos of atoms from 2+ elements
-chemical reactions occur from rearrangement of atoms
22. What increases the number of electrons to be emitted by the photoelectric
effect?
Answer: Intensity.
23. JJ Thomson
Answer: -first person to provide evidence of electron
-cathode ray tube
-plum pudding model
-particles carried electric charge
