CEM 141 Final Exam (New 2026/ 2027
Update) Questions & Answers {Grade A}
100% Correct (Verified Solutions) -MSU
What is the evidence that supports the claim that light is a particle?
a. When light shines through a double slit, the light produces an interference pattern.
b. Increasing the amplitude makes light appear brighter
c. When light shines on metal, there is a threshold frequency, below which no
electrons are ejected from a metal.
d. Electrons produce an interference pattern.
e. Electrons absorb certain photons of light to move to higher energy levels. The
electrons can emit the photon to move back to the lower energy level. - Correct
answer When light shines on metal, there is a threshold frequency, below which no
electrons are ejected from a metal.
An MRI machine operates at a frequency of 30 kilohertz (kHz), what wavelength
radiation does this correspond to?
a. 1x10^10 m
b. 1x10^7 m
,c. 1x10^5 m
d. 1x10^4 m - Correct answer 1x10^4 m
Why must we consider the wave properties of an electron, but not the wave properties
of macroscopic objects (such as humans)?
a. Only very small pieces of matter (such as electrons) are waves, whereas
macroscopic objects are not.
b. We can calculate the wavelength of an electron but cannot calculate the wavelength
for a macroscopic object using the de Broglie equation.
c. The wavelength of the electron is similar in size to the atom and affects its
properties, whereas the wavelength of the macroscopic object is much smaller than
the object and does not affect its properties.
d. We cannot tell if electrons are waves or particles because they are too small to see.
Since we can see macroscopic objects, we can confirm they are not waves. - Correct
answer The wavelength of the electron is similar in size to the atom and affects its
properties, whereas the wavelength of the macroscopic object is much smaller than
the object and does not affect its properties.
, Write the electron configuration for fluorine (F) and the electron configuration for
chlorine (Cl). What is different about the valence electrons in these two atoms?
I. There are different numbers of valence electrons
II. The valence electrons have different energies
III. The valence electrons are in different types of orbitals (s, p, d, f).
IV. The valence electrons are in different size orbitals. - Correct answer The valence
electrons have different energies
The valence electrons are in different size orbitals
What is the electron configuration of Mg+?
a. 1s2,2s2,2p6,3s2
b. 1s2,2s2,2p6,3s1
c. 1s2,2s2,2p6
d. 1s2,2s2,2p5
e. 1s2,2s2,2p6,3s2,3p3
f. 1s2,2s2,2p6,3s2,3p4 - Correct answer 1s2,2s2,2p6,3s1
Consider K+ and Cl-. Which do you predict is larger and why?
Update) Questions & Answers {Grade A}
100% Correct (Verified Solutions) -MSU
What is the evidence that supports the claim that light is a particle?
a. When light shines through a double slit, the light produces an interference pattern.
b. Increasing the amplitude makes light appear brighter
c. When light shines on metal, there is a threshold frequency, below which no
electrons are ejected from a metal.
d. Electrons produce an interference pattern.
e. Electrons absorb certain photons of light to move to higher energy levels. The
electrons can emit the photon to move back to the lower energy level. - Correct
answer When light shines on metal, there is a threshold frequency, below which no
electrons are ejected from a metal.
An MRI machine operates at a frequency of 30 kilohertz (kHz), what wavelength
radiation does this correspond to?
a. 1x10^10 m
b. 1x10^7 m
,c. 1x10^5 m
d. 1x10^4 m - Correct answer 1x10^4 m
Why must we consider the wave properties of an electron, but not the wave properties
of macroscopic objects (such as humans)?
a. Only very small pieces of matter (such as electrons) are waves, whereas
macroscopic objects are not.
b. We can calculate the wavelength of an electron but cannot calculate the wavelength
for a macroscopic object using the de Broglie equation.
c. The wavelength of the electron is similar in size to the atom and affects its
properties, whereas the wavelength of the macroscopic object is much smaller than
the object and does not affect its properties.
d. We cannot tell if electrons are waves or particles because they are too small to see.
Since we can see macroscopic objects, we can confirm they are not waves. - Correct
answer The wavelength of the electron is similar in size to the atom and affects its
properties, whereas the wavelength of the macroscopic object is much smaller than
the object and does not affect its properties.
, Write the electron configuration for fluorine (F) and the electron configuration for
chlorine (Cl). What is different about the valence electrons in these two atoms?
I. There are different numbers of valence electrons
II. The valence electrons have different energies
III. The valence electrons are in different types of orbitals (s, p, d, f).
IV. The valence electrons are in different size orbitals. - Correct answer The valence
electrons have different energies
The valence electrons are in different size orbitals
What is the electron configuration of Mg+?
a. 1s2,2s2,2p6,3s2
b. 1s2,2s2,2p6,3s1
c. 1s2,2s2,2p6
d. 1s2,2s2,2p5
e. 1s2,2s2,2p6,3s2,3p3
f. 1s2,2s2,2p6,3s2,3p4 - Correct answer 1s2,2s2,2p6,3s1
Consider K+ and Cl-. Which do you predict is larger and why?
