CEM 141 FINAL EXAM Questions with Detailed
Verified Answers
Out of Dalton's, Rutherford's and Thompson's model, which model would support
the claim that "atoms are composed of mostly empty space"? Ans: Rutherford's
planetary model
"Does the planet Venus have phases (for example full or quarter) like the moon?" Is
this question a scientific question? Ans: Yes, because it can be tested and answered
through observations and experiments.
As two protons move toward each other, the potential energy of the system will...
Ans: increase because of the repulsive force between the like charges.
One part of Dalton's Atomic Theory states:"Compounds are formed by combinations
of atoms from two or more elements." Is this statement currently considered to be
true or false and why? Ans: True because by definition a compound must have at least
two types of elements.
Thompson observed that the type of metal used for the cathode did not affect the
behavior of the cathode ray. What claim does this piece of evidence support? Ans: All
atoms contain electrons.
At which point are the atoms the most stable on the potential energy diagram? Ans:
At the well because the attractive and repulsive forces are balanced.
How would energy change as two helium atoms move from where it says "attractive
force" in the diagram to where it says "most stable state" in the diagram? Ans: The
kinetic energy will increase as the potential energy decreases while the total energy
doesn't change.
What causes the change in the potential energy when the two helium atoms move
from where it says "attractive forces" to where it says "most stable state" in the
diagram? Ans: Attractive force
, Consider a container of xenon atoms where two xenon atoms of interest are
interacting(the system) and are surrounded by other xenon atoms. The surrounding
xenon atoms have more energy than the two xenon atoms in the system. Which
direction would you predict the energy would transferred and what would happen?
Ans: During a collision energy will be transferred from the surrounding xenon atoms
to the system of the two xenon atoms and the stable interactions will be overcome.
How would the strength of the electrostatic force change if the distance between two
charged objects increased? Ans: The electrostatic force would become weaker.
Which of the following statements are true for both London Dispersion Forces and
covalent Bonds? Ans: They are both attractive interactions and They both release
energy when they are formed.
When oxygen boils ... Ans: London dispersion forces between the O2 molecules are
overcome.
You are asked to compare the interactions between atoms of two substances,
substance X and substance Y. When you look at the graph showing how potential
energy changed as distance between the atoms changes, you notice that substance Y
has a much deeper potential energy well than X. From this information, you conclude...
Ans: Atoms of Y interact to form covalent bonds because covalent bonds are stronger
than LDFs and require more energy to break.
Which of the following contains the largest number of molecules?
a) 15.0g Br2
b) 15.0g Cl2
c) 15.0g O2 Ans: c) 15.0g O2
What is the mass of two moles of Mg3(PO4)2? Ans: 525.7 g
© Get it right 2025 Getaway - Stuvia US All rights reserved
Verified Answers
Out of Dalton's, Rutherford's and Thompson's model, which model would support
the claim that "atoms are composed of mostly empty space"? Ans: Rutherford's
planetary model
"Does the planet Venus have phases (for example full or quarter) like the moon?" Is
this question a scientific question? Ans: Yes, because it can be tested and answered
through observations and experiments.
As two protons move toward each other, the potential energy of the system will...
Ans: increase because of the repulsive force between the like charges.
One part of Dalton's Atomic Theory states:"Compounds are formed by combinations
of atoms from two or more elements." Is this statement currently considered to be
true or false and why? Ans: True because by definition a compound must have at least
two types of elements.
Thompson observed that the type of metal used for the cathode did not affect the
behavior of the cathode ray. What claim does this piece of evidence support? Ans: All
atoms contain electrons.
At which point are the atoms the most stable on the potential energy diagram? Ans:
At the well because the attractive and repulsive forces are balanced.
How would energy change as two helium atoms move from where it says "attractive
force" in the diagram to where it says "most stable state" in the diagram? Ans: The
kinetic energy will increase as the potential energy decreases while the total energy
doesn't change.
What causes the change in the potential energy when the two helium atoms move
from where it says "attractive forces" to where it says "most stable state" in the
diagram? Ans: Attractive force
, Consider a container of xenon atoms where two xenon atoms of interest are
interacting(the system) and are surrounded by other xenon atoms. The surrounding
xenon atoms have more energy than the two xenon atoms in the system. Which
direction would you predict the energy would transferred and what would happen?
Ans: During a collision energy will be transferred from the surrounding xenon atoms
to the system of the two xenon atoms and the stable interactions will be overcome.
How would the strength of the electrostatic force change if the distance between two
charged objects increased? Ans: The electrostatic force would become weaker.
Which of the following statements are true for both London Dispersion Forces and
covalent Bonds? Ans: They are both attractive interactions and They both release
energy when they are formed.
When oxygen boils ... Ans: London dispersion forces between the O2 molecules are
overcome.
You are asked to compare the interactions between atoms of two substances,
substance X and substance Y. When you look at the graph showing how potential
energy changed as distance between the atoms changes, you notice that substance Y
has a much deeper potential energy well than X. From this information, you conclude...
Ans: Atoms of Y interact to form covalent bonds because covalent bonds are stronger
than LDFs and require more energy to break.
Which of the following contains the largest number of molecules?
a) 15.0g Br2
b) 15.0g Cl2
c) 15.0g O2 Ans: c) 15.0g O2
What is the mass of two moles of Mg3(PO4)2? Ans: 525.7 g
© Get it right 2025 Getaway - Stuvia US All rights reserved
