Quantum Theory
Practice Test
1.
The threshold frequency is the frequency at which kinetic energy is equal to __________.
a.
h
b.
zero
c.
hf
0
d.
hf
Hint
2.
What is the de Broglie wavelength of an electron moving at 3.0×10
6
m/s?
a.
0.24 m
b.
0.12 nm
c.
0.49 m
d.
0.24 nm
Hint
3.
Einstein predicted that photons had two properties of particles: __________ and __________.
a.
energy; mass
b.
mass; momentum
c.
momentum; diffraction
d.
energy; momentum
Hint
4.
An electron is accelerated by a potential difference of 150 V, giving it a velocity of 7.3×10
6
m/s. What is the de Broglie wavelength of this electron?
a.
9.5×10
11
m
b.
4.9×10
-11
m
c.
9.5×10
-11
m
d.
5.9×10
-24
m
Hint
