CEM 141 MSU FINAL EXAM
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS
Is this a scientific question: Is there an attractive force between a pencil and the earth?
I. Yes
II. No
Because
III. It can be tested and answered through observations and experiments.
IV. The answer is already known and we find it online.
V. There is no way to design an experiment to answer this question. - ANSWERSI and
III: Yes, it can be tested and answered through observations and experiments.
Which of the following properties ascribed to atoms by the greeks do we still count as
valid?
I. The size and the shape of the atoms determine a material's properties.
II. Atoms are indivisible.
III. Atoms are in constant motion. - ANSWERSIII: atoms are in constant motion
Electrons are negatively charged. Which experiment provided evidence to support this
claim?
Experiment:
I. The gold foil experiment.
II. The cathode ray tube experiment.
Evidence:
III. Most of the positively charged alpha particles shot at a thin gold foil passed straight
through.
IV. A small fraction of the positively charged alpha particles shot at a thin gold foil were
deflected.
V. The beam of particles emitted from the cathode bent toward the positively charged
plate.
VI. The beam of particles emitted from the cathode behaved the same no matter what
type of metal the cathode was made of. - ANSWERSII and V: The cathode ray tube
experiment; the beam of particles emitted from the cathode bent toward the positively
charged plate.
Which of the following contains atoms?
a. heat
b. light
c. energy
, d. dust
e. all of the above - ANSWERSd. dust
Thomson's cathode ray tube experiment proved false what part of Dalton's atomic
theory?
a. All atoms are indivisible and indestructible.
b. All atoms of a given element are identical.
c. All matter is made of atoms.
d. Compounds are formed from the combination of two or more elements.
e. Chemical reactions are rearrangements of atoms. - ANSWERSa. all atoms are
indivisible and indestructible.
How would the strength of the electrostatic force change if the distance between two
charged objects decreased?
a. The electrostatic force would become stronger.
b. The electrostatic force would become weaker.
c. The electrostatic force would become stronger or weaker depending on whether the
force is attractive or repulsive.
d. It is impossible to say from the information given. - ANSWERSa. the electrostatic
force would become stronger
Consider the following statement: "A nitrogen molecule is made of the same type of
atoms." Is this statement true or false and why?
I. True
II. False
Because:
III. An element is made of one type of atom. Nitrogen is an element that exists as
diatomic molecules.
IV. Nitrogen is a compound that exists as diatomic molecules. Compounds are made of
different types of atoms.
V. Nitrogen is an element, and therefore must exist as separate atoms not molecules.
a. I and III c. I and V e. II and IV
b. I and IV d. II and III f. II and V - ANSWERSa. I and III
true, because an element is made of one type of atom. Nitrogen is an element that
exists as diatomic molecules
Why does the potential energy increase as two xenon atoms move extremely close
together?
a. Because the kinetic energy decreases as the atoms slow down.
b. Because the electrostatic attractive force, from the instantaneous dipoles, is
dominant.
c. Because the repulsive force, between the overlapping electron clouds, is dominant.
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS
Is this a scientific question: Is there an attractive force between a pencil and the earth?
I. Yes
II. No
Because
III. It can be tested and answered through observations and experiments.
IV. The answer is already known and we find it online.
V. There is no way to design an experiment to answer this question. - ANSWERSI and
III: Yes, it can be tested and answered through observations and experiments.
Which of the following properties ascribed to atoms by the greeks do we still count as
valid?
I. The size and the shape of the atoms determine a material's properties.
II. Atoms are indivisible.
III. Atoms are in constant motion. - ANSWERSIII: atoms are in constant motion
Electrons are negatively charged. Which experiment provided evidence to support this
claim?
Experiment:
I. The gold foil experiment.
II. The cathode ray tube experiment.
Evidence:
III. Most of the positively charged alpha particles shot at a thin gold foil passed straight
through.
IV. A small fraction of the positively charged alpha particles shot at a thin gold foil were
deflected.
V. The beam of particles emitted from the cathode bent toward the positively charged
plate.
VI. The beam of particles emitted from the cathode behaved the same no matter what
type of metal the cathode was made of. - ANSWERSII and V: The cathode ray tube
experiment; the beam of particles emitted from the cathode bent toward the positively
charged plate.
Which of the following contains atoms?
a. heat
b. light
c. energy
, d. dust
e. all of the above - ANSWERSd. dust
Thomson's cathode ray tube experiment proved false what part of Dalton's atomic
theory?
a. All atoms are indivisible and indestructible.
b. All atoms of a given element are identical.
c. All matter is made of atoms.
d. Compounds are formed from the combination of two or more elements.
e. Chemical reactions are rearrangements of atoms. - ANSWERSa. all atoms are
indivisible and indestructible.
How would the strength of the electrostatic force change if the distance between two
charged objects decreased?
a. The electrostatic force would become stronger.
b. The electrostatic force would become weaker.
c. The electrostatic force would become stronger or weaker depending on whether the
force is attractive or repulsive.
d. It is impossible to say from the information given. - ANSWERSa. the electrostatic
force would become stronger
Consider the following statement: "A nitrogen molecule is made of the same type of
atoms." Is this statement true or false and why?
I. True
II. False
Because:
III. An element is made of one type of atom. Nitrogen is an element that exists as
diatomic molecules.
IV. Nitrogen is a compound that exists as diatomic molecules. Compounds are made of
different types of atoms.
V. Nitrogen is an element, and therefore must exist as separate atoms not molecules.
a. I and III c. I and V e. II and IV
b. I and IV d. II and III f. II and V - ANSWERSa. I and III
true, because an element is made of one type of atom. Nitrogen is an element that
exists as diatomic molecules
Why does the potential energy increase as two xenon atoms move extremely close
together?
a. Because the kinetic energy decreases as the atoms slow down.
b. Because the electrostatic attractive force, from the instantaneous dipoles, is
dominant.
c. Because the repulsive force, between the overlapping electron clouds, is dominant.
