Section 27.2
Matter Waves
Practice Test
1.
An electron has a de Broglie wavelength of 750 nm. Find the velocity of the electron.
a.
970 m/s
b.
180 m/s
c.
6600 m/s
d.
9700 m/s
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.
According to de Broglie, electrons and protons should show __________ properties.
a.
radioactive
b.
explosive
c.
unstable
d.
wave
Hint
4.
For the situation depicted in Figure 27-13, what would the kinetic energy of the ejected electrons be if the incident radiation had a wavelength of 200.0 nm and the metal had a work function of 2.56 eV?
a.
3.64 eV
b.
1.25 eV
c.
2.56 eV
d.
2.40 eV
Hint
5.
According to Figure 27-6, what is the approximate frequency needed to eject an electron with a minimum kinetic energy of 5 eV?
a.
20×10
14
Hz
b.
It cannot be determined from the graph.
c.
16×10
14
Hz
d.
12×10
14
Hz
Hint
6.
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.
5.9×10
-24
m
b.
9.5×10
11
m
c.
9.5×10
-11
m
d.
4.9×10
-11
m
Hint
7.
In the situation depicted in Figure 27-12, if the electron's initial kinetic energy is doubled, what stopping potential would be required?
a.
25.0 V
b.
2.5 V
c.
5.0 V
d.
10.0 V
Hint
8.
The Heisenberg uncertainty principle states that it is impossible to precisely measure the __________ of a particle at the same time.
a.
momentum and frequency
b.
position and energy
c.
position and momentum
d.
frequency and energy
Hint
9.
In the situation depicted in Figure 27-12, if the electron's initial speed is doubled, what stopping potential would be required?
a.
10.0 V
b.
20.0 V
c.
5.0 V
d.
2.5 V
Hint
10.
According to Figure 27-6, what is the approximate frequency needed to eject an electron with a minimum kinetic energy of 2 eV?
a.
9.2×10
14
Hz
b.
4.5×10
14
Hz
c.
10×10
14
Hz
d.
8.1×10
14
Hz
Hint
