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Michigan State University
CEM 141 Chem Exam Pt 3 Questions and
Answers 2026 Latest Update
What happens to the ELECTROSTATIC FORCE as two atoms of Ne approach
each other— Ans: It increases because the distance between the attractive
forces decreases
If atoms get TOO close the electron clouds begin to overlap and the
electrostatic repulsive force becomes dominant causing— Ans: the potential
energy to increase because the atoms are now moving AGAINST that
dominant, repulsive force
Which force is strongest as atoms move closer to each other?— Ans:
Electrostatic attraction
Which force is the strongest as atoms move even CLOSER?— Ans:
Electrostatic repulsion
Where are LDF's formed?— Ans: At the bottom of the well on a PE graph.
This is where there is balanced energy; electrostatic repulsion=electrostatic
attraction
As two atoms approach each other, potential energy— Ans: decreases
because they are moving with the dominant force (the attraction)
As they move VERY CLOSE together =, potential energy— Ans: increases
because they are now moving against the dominant attractive force (the
atoms have now become repulsive + + or - -)
When two atoms approach what happens to the TOTAL energy?— Ans: It
stays the same because the total energy of the system is isolated (not
interacting)
© 2026 All rights reserved
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When two atoms approach what happens to the KINETIC energy?— Ans: It
increases because the as the atoms get closer, attraction gets stronger,
causing the atoms to speed up.
When two atoms approach what happens to the POTENTIAL energy?— Ans:
It decreases because the attractive force is the dominant force & the atoms
are moving WITH the dominant force, causing the energy to decrease.
When two same signed atoms approach each other what happens to
POTENTIAl energy?— Ans: It increases because now, the dominant force is
repulsion, which works against the force of attraction as we move them even
closer. It requires more energy for two atoms to repel each other.
When two same signed atoms approach each other what happens to
KINETIC energy?— Ans: It decreases because the repulsive force takes over
so the atoms begin to slow down.
Why don't atoms STAY in the potential minimum?— Ans: Because there is
TOO much energy
How can we get the atoms to stay in the potential minimum?— Ans: We can
have a collision or cool the system down. Our system has to be RELEASED of
some energy.
What can the position of PE tell you?— Ans: The distance between the atom
centers at the most stable point
What can the depth of the PE well tell you?— Ans: How much energy would
be needed to overcome the interaction & how strong the interaction is
between the atoms
**The deeper the well, the stronger the interaction is & the more energy is
needed to break the interaction
How do we break the LDF's?— Ans: Add energy! (heat atoms up)
-this energy comes from the surroundings
What happens when thermal energy is added to atoms?— Ans: The
surrounding atoms speed up & collide with other atoms and kinetic energy
is transferred through collision to the atoms, causing them to separate from
each other.
© 2026 All rights reserved
Michigan State University
CEM 141 Chem Exam Pt 3 Questions and
Answers 2026 Latest Update
What happens to the ELECTROSTATIC FORCE as two atoms of Ne approach
each other— Ans: It increases because the distance between the attractive
forces decreases
If atoms get TOO close the electron clouds begin to overlap and the
electrostatic repulsive force becomes dominant causing— Ans: the potential
energy to increase because the atoms are now moving AGAINST that
dominant, repulsive force
Which force is strongest as atoms move closer to each other?— Ans:
Electrostatic attraction
Which force is the strongest as atoms move even CLOSER?— Ans:
Electrostatic repulsion
Where are LDF's formed?— Ans: At the bottom of the well on a PE graph.
This is where there is balanced energy; electrostatic repulsion=electrostatic
attraction
As two atoms approach each other, potential energy— Ans: decreases
because they are moving with the dominant force (the attraction)
As they move VERY CLOSE together =, potential energy— Ans: increases
because they are now moving against the dominant attractive force (the
atoms have now become repulsive + + or - -)
When two atoms approach what happens to the TOTAL energy?— Ans: It
stays the same because the total energy of the system is isolated (not
interacting)
© 2026 All rights reserved
, 2 | Page
When two atoms approach what happens to the KINETIC energy?— Ans: It
increases because the as the atoms get closer, attraction gets stronger,
causing the atoms to speed up.
When two atoms approach what happens to the POTENTIAL energy?— Ans:
It decreases because the attractive force is the dominant force & the atoms
are moving WITH the dominant force, causing the energy to decrease.
When two same signed atoms approach each other what happens to
POTENTIAl energy?— Ans: It increases because now, the dominant force is
repulsion, which works against the force of attraction as we move them even
closer. It requires more energy for two atoms to repel each other.
When two same signed atoms approach each other what happens to
KINETIC energy?— Ans: It decreases because the repulsive force takes over
so the atoms begin to slow down.
Why don't atoms STAY in the potential minimum?— Ans: Because there is
TOO much energy
How can we get the atoms to stay in the potential minimum?— Ans: We can
have a collision or cool the system down. Our system has to be RELEASED of
some energy.
What can the position of PE tell you?— Ans: The distance between the atom
centers at the most stable point
What can the depth of the PE well tell you?— Ans: How much energy would
be needed to overcome the interaction & how strong the interaction is
between the atoms
**The deeper the well, the stronger the interaction is & the more energy is
needed to break the interaction
How do we break the LDF's?— Ans: Add energy! (heat atoms up)
-this energy comes from the surroundings
What happens when thermal energy is added to atoms?— Ans: The
surrounding atoms speed up & collide with other atoms and kinetic energy
is transferred through collision to the atoms, causing them to separate from
each other.
© 2026 All rights reserved
