CEM 141 MSU EXAM 2 QUESTIONS
WITH CORRECT ANSWERS (VERIFIED
SOLUTIONS) ||100% GUARANTEED
PASS||UPDATED 2026/2027
SYLLABUS||ALREADY GRADED||
What is the concept of a mole and what is it used for? - ANSWER ✓ Translation
between molecular and macroscopic scale.
Why does adding energy in the form of a light (EM radiation) allow electrons to
"escape?" - ANSWER ✓ The photoelectric effect.
What happens to the wavelength if the frequency increases? - ANSWER ✓
Decreases.
What happens to the frequency when the wavelength increases? - ANSWER ✓
Decreases.
How is absorption and emission different from photoelectric effect? - ANSWER
✓ In the photoelectric effect, an atom absorbs a photo resulting in the ejection of
an electron.
What is the evidence that electrons are waves? - ANSWER ✓ Double slit
experiment.
Atomic radius ______ down a group. - ANSWER ✓ Increases.
Atomic radius ______ across a row. - ANSWER ✓ Decreases.
Ionic Radius - ANSWER ✓ Ions are atoms in which electrons have been added or
removed.
,If an electron is removed from an atom, what is the charge of the ion? - ANSWER
✓ Positive (cation).
If an electron is added to an atom, what is the charge of the ion? - ANSWER ✓
Negative (anion).
Who developed the Periodic Table? - ANSWER ✓ Mendeleev.
Li/Na. Which is easier to remove an electron from? - ANSWER ✓ Na.
The ionization energy of Na is __________ than Li? - ANSWER ✓ Smaller
The wavelength of the electron that you calculate in question 25 is closest in size
to.... - ANSWER ✓ diameter of a carbon nanotube
If the intensity of a beam of light is increased, this would correspond to.... -
ANSWER ✓ - An increase in the number of photons (considering light as a
particle).
- An increase in the amplitude of the wave (considering light as a wave).
For a given photocell (a device that uses the photoelectric effect to generate
electricity), blue light will eject electrons, but red light will not. Why? - ANSWER
✓ Photons of blue light each have enough energy to eject one electron.
What is the wavelength of light that has a frequency of 3.0 GHz (3 x 10^6 Hz)? -
ANSWER ✓ 100 m
What wavelength of light would break a O=O bond (it takes 8.3 x 10^-19 J to
break one bond)? - ANSWER ✓ 240 nm
How does the existence of atoms help explain the conversion of matter? -
ANSWER ✓ The existence of atoms shows that matter is conserved because the
reaction has to be balanced. There cannot just be a random atom put in or taken
out. Both sides have to have the same amount of atoms.
Atomic absorption spectra are caused by.... - ANSWER ✓ Electrons moving to
higher energy levels and absorbing photons of energy equal to the energy
difference between the levels.
, How many core and valence electrons does carbon have? - ANSWER ✓ 2 core, 4
valence
What is the electron configuration of Se? - ANSWER ✓ [Ar] 4s^2 3d^10 4p^4
Molar Mass - ANSWER ✓ mass of 1 mole in grams
What is the best explanation for a pattern such as those obtained when X-Rays are
diffracted by crystals? - ANSWER ✓ The waves of electromagnetic radiation
arrive in-phase and out of phase at the detector.
The first ionization energy of an element in the third row (Na-Ar) of the periodic
table is 578 kJ/mol, its second IE is 1820, the 3rd is 2750 and the 4th is 11600, and
the 5th is 14842. Which element do you think this is? - ANSWER ✓ Aluminum
How many grams of N2 would be required to produce 2.75 moles of NH3? -
ANSWER ✓ 38.5g N2
How many moles of Ca(NO3)2 are in 325g? - ANSWER ✓ 1.98 mole Ca(NO3)2
How much Carbon Dioxide would be produced if 10 kg of methane are combusted
in excess oxygen? - ANSWER ✓ 27,500 g CO2
How much carbon dioxide would be
produced if an excess of methane is
combusted in 10 g oxygen? - ANSWER ✓ 6.9g of CO2
How many moles of NH3 would be produced if 6 moles of H2 reacted with 3
moles of N2? - ANSWER ✓ 6 mole of NH3
Limiting Reactant - ANSWER ✓ Calculate the amount of product possible from
each reactant. Whichever produces the least
product is the limiting reactant.
Percent Yield - ANSWER ✓ (actual amount produced/theoretical amount) x 100
What is the percent yield of the reaction if 32.8 g of
WITH CORRECT ANSWERS (VERIFIED
SOLUTIONS) ||100% GUARANTEED
PASS||UPDATED 2026/2027
SYLLABUS||ALREADY GRADED||
What is the concept of a mole and what is it used for? - ANSWER ✓ Translation
between molecular and macroscopic scale.
Why does adding energy in the form of a light (EM radiation) allow electrons to
"escape?" - ANSWER ✓ The photoelectric effect.
What happens to the wavelength if the frequency increases? - ANSWER ✓
Decreases.
What happens to the frequency when the wavelength increases? - ANSWER ✓
Decreases.
How is absorption and emission different from photoelectric effect? - ANSWER
✓ In the photoelectric effect, an atom absorbs a photo resulting in the ejection of
an electron.
What is the evidence that electrons are waves? - ANSWER ✓ Double slit
experiment.
Atomic radius ______ down a group. - ANSWER ✓ Increases.
Atomic radius ______ across a row. - ANSWER ✓ Decreases.
Ionic Radius - ANSWER ✓ Ions are atoms in which electrons have been added or
removed.
,If an electron is removed from an atom, what is the charge of the ion? - ANSWER
✓ Positive (cation).
If an electron is added to an atom, what is the charge of the ion? - ANSWER ✓
Negative (anion).
Who developed the Periodic Table? - ANSWER ✓ Mendeleev.
Li/Na. Which is easier to remove an electron from? - ANSWER ✓ Na.
The ionization energy of Na is __________ than Li? - ANSWER ✓ Smaller
The wavelength of the electron that you calculate in question 25 is closest in size
to.... - ANSWER ✓ diameter of a carbon nanotube
If the intensity of a beam of light is increased, this would correspond to.... -
ANSWER ✓ - An increase in the number of photons (considering light as a
particle).
- An increase in the amplitude of the wave (considering light as a wave).
For a given photocell (a device that uses the photoelectric effect to generate
electricity), blue light will eject electrons, but red light will not. Why? - ANSWER
✓ Photons of blue light each have enough energy to eject one electron.
What is the wavelength of light that has a frequency of 3.0 GHz (3 x 10^6 Hz)? -
ANSWER ✓ 100 m
What wavelength of light would break a O=O bond (it takes 8.3 x 10^-19 J to
break one bond)? - ANSWER ✓ 240 nm
How does the existence of atoms help explain the conversion of matter? -
ANSWER ✓ The existence of atoms shows that matter is conserved because the
reaction has to be balanced. There cannot just be a random atom put in or taken
out. Both sides have to have the same amount of atoms.
Atomic absorption spectra are caused by.... - ANSWER ✓ Electrons moving to
higher energy levels and absorbing photons of energy equal to the energy
difference between the levels.
, How many core and valence electrons does carbon have? - ANSWER ✓ 2 core, 4
valence
What is the electron configuration of Se? - ANSWER ✓ [Ar] 4s^2 3d^10 4p^4
Molar Mass - ANSWER ✓ mass of 1 mole in grams
What is the best explanation for a pattern such as those obtained when X-Rays are
diffracted by crystals? - ANSWER ✓ The waves of electromagnetic radiation
arrive in-phase and out of phase at the detector.
The first ionization energy of an element in the third row (Na-Ar) of the periodic
table is 578 kJ/mol, its second IE is 1820, the 3rd is 2750 and the 4th is 11600, and
the 5th is 14842. Which element do you think this is? - ANSWER ✓ Aluminum
How many grams of N2 would be required to produce 2.75 moles of NH3? -
ANSWER ✓ 38.5g N2
How many moles of Ca(NO3)2 are in 325g? - ANSWER ✓ 1.98 mole Ca(NO3)2
How much Carbon Dioxide would be produced if 10 kg of methane are combusted
in excess oxygen? - ANSWER ✓ 27,500 g CO2
How much carbon dioxide would be
produced if an excess of methane is
combusted in 10 g oxygen? - ANSWER ✓ 6.9g of CO2
How many moles of NH3 would be produced if 6 moles of H2 reacted with 3
moles of N2? - ANSWER ✓ 6 mole of NH3
Limiting Reactant - ANSWER ✓ Calculate the amount of product possible from
each reactant. Whichever produces the least
product is the limiting reactant.
Percent Yield - ANSWER ✓ (actual amount produced/theoretical amount) x 100
What is the percent yield of the reaction if 32.8 g of
