A laser emits photons
- A laser emits photons having an energy of 4.09´10-19J. What wavelength of light would this laser have?
(.00×108 m/s, h= 6.63×10-34J⋅s)
Select one:
a. 8.11×10−44 m
b. 0.0021 nm
c. 4.86×10−7 nm
d. 486 nm
e. 372 nm
2. What is the wavelength of a photon having a frequency of 44.6×1015 Hz
(c = 3.00 × 108 m/s, h = 6.63 ×10−34 J ⋅ s)
Select one:
a. 0.215 nm
b. 4.28×10−23 nm
c. 1.28×10−14 nm
d. 6.73 nm
e. 6.73×1015 nm
3. What is the wavelength of light emitted when the electron in a hydrogen atom undergoes a transition from level
n= 5 to n= 2? n= 5 to n= 2?
(.00×108 m/s, .63×10−34 J⋅s, .179×10−18 J)
Select one:
a. 9.39×10−7m
b. 4.34×10−7m
c. 1.07×107m
d. 2.12×10−18m
e. 3.20×1015m
4. When a particular metal is illuminated with photons, one electron is observed for each absorbed photon. What effect would increasing the wavelength and number of photons have on the electrons leaving the surface?
Select one:
a. There would be more electrons leaving the surface.
b. They would have higher kinetic energy.
c. The electron velocity would be lower.
d. The kinetic energy of the electrons would be the same for each electron ejected, but less electrons would be ejected.
e. Two photons might be required to eject the electrons.
5. Which of the following is/are incorrect postulates of Bohr's theory of the hydrogen atom?
1.The energy of an electron in an atom is quantized (i.e. only specific energy values are possible).
2.The principal quantum number (n), specifies each unique energy level.
3.An electron transition from a lower energy level to a higher energy level results in an emission of a photon of light.
Select one:
a. 1 only
b. 2 only
c. 3 only
d. 1 and 2
e. 1, 2, and 3
6. Which type of electromagnetic radiation has the lowest frequency?
Select one:
a. Microwaves
b. Visible
c. radio waves
d. Infrared
e. ultraviolet
7. A possible value of the magnetic quantum number ml for a 3p electron is
Select one:
a. 1
b. 2
c. -5
d. 6
e. 4
8. What is the wavelength of a 543-g baseball traveling at 76.2 mph? (1 .609 km, .63×10−34 J⋅s)
Select one:
a. 2.91×10−37
b. 3.58×10−35m
c. 1.02×10−37m
d. 9.76×1033m
e. 2.85×10−38m
9. Which of the following sets of quantum numbers (n, l, ml, ms) refers to a 4d orbital?
Select one:
a. 2 1 0 +1/2
b. 5 4 3 +1/2
c. 4 2 1 −1/2
d. 4 3 1 −1/2
e. 3 2 1 −1/2
10. Which quantum number distinguishes the energy of an electron?
Select one:
a. n
b. ml
c. l
d. ms
e. any of these