CEM 141
CEM 141 MSU Exam 3 Study Questions and
Answers Graded A+ 2026
Ionization Energy -Correct Answer ✔-energy required to remove an electron from an
atom in the gas phase
Left Side Electrons -Correct Answer ✔-have weaker attractions to remove electrons
*easier to remove electrons from the left side of the table than the right side*
Does it take MORE or LESS energy to remove an electron from Li than from Na? -
Correct Answer ✔-MORE
Why? Because as we move down a group, the orbitals become larger and weaker.
While going across the effective nuclear charge increases. (holds onto the electrons
tighter)
Big Bang evidence -Correct Answer ✔-universe is expanding (red shift)
Where do atoms come from? -Correct Answer ✔-The Big Bang
What were elements formed by? -Correct Answer ✔-Nuclear reactions
Chemical reactions -Correct Answer ✔-involve rearrangements of valence electrons
*the element undergoing a chemical reaction does not ever change*
Ionization energies are affected by -Correct Answer ✔--size of an atom
-size of positive charge
Periodic Trends -Correct Answer ✔--small atoms have higher ionization energies
-they are inversely related
Atomic Radius Decreases ----> Ionization energy increases -Correct Answer ✔-when
the radius decreases, it pulls the electrons closer. decreasing the size of an atom
Nuclear Reactions -Correct Answer ✔-Fusion and Fission
Fusion -Correct Answer ✔-two lighter nuclei combines to form a heavier nucleus
(energy released)
Fission -Correct Answer ✔-a heavier nucleus is broken a part to form lighter, more
stable nuclei energy
Atomic # = -Correct Answer ✔-# of protons
CEM 141
CEM 141 MSU Exam 3 Study Questions and
Answers Graded A+ 2026
Ionization Energy -Correct Answer ✔-energy required to remove an electron from an
atom in the gas phase
Left Side Electrons -Correct Answer ✔-have weaker attractions to remove electrons
*easier to remove electrons from the left side of the table than the right side*
Does it take MORE or LESS energy to remove an electron from Li than from Na? -
Correct Answer ✔-MORE
Why? Because as we move down a group, the orbitals become larger and weaker.
While going across the effective nuclear charge increases. (holds onto the electrons
tighter)
Big Bang evidence -Correct Answer ✔-universe is expanding (red shift)
Where do atoms come from? -Correct Answer ✔-The Big Bang
What were elements formed by? -Correct Answer ✔-Nuclear reactions
Chemical reactions -Correct Answer ✔-involve rearrangements of valence electrons
*the element undergoing a chemical reaction does not ever change*
Ionization energies are affected by -Correct Answer ✔--size of an atom
-size of positive charge
Periodic Trends -Correct Answer ✔--small atoms have higher ionization energies
-they are inversely related
Atomic Radius Decreases ----> Ionization energy increases -Correct Answer ✔-when
the radius decreases, it pulls the electrons closer. decreasing the size of an atom
Nuclear Reactions -Correct Answer ✔-Fusion and Fission
Fusion -Correct Answer ✔-two lighter nuclei combines to form a heavier nucleus
(energy released)
Fission -Correct Answer ✔-a heavier nucleus is broken a part to form lighter, more
stable nuclei energy
Atomic # = -Correct Answer ✔-# of protons
CEM 141
