CEM 141 EXAM 3 2026 STOICHIOMETRY AND
CALCULATIONS WORKBOOK SOLVED
QUESTIONS COMPILATION
◉ What is the trend for atomic radius when moving down a group in
the periodic table?
Answer: The atomic radius increases.
◉ How does ionization energy typically change across a period from
left to right?
Answer: The ionization energy increases
◉ The net positive charge felt by valence electrons after accounting
for shielding is known as ____.
Answer: Effective nuclear charge (Zeff)
◉ According to Coulomb's Law, what is the relationship between the
force of attraction (F) and the distance (r) between charges?
Answer:
◉ Why does a higher effective nuclear charge (Zeff) lead to a smaller
atomic radius?
, Answer: The stronger the positive charge pulls electrons closer to
the nucleus.
◉ What evidence supports the idea that electron energy levels in
atoms are quantized?
Answer: The existence of large, discrete jumps in successive
ionization energies.
◉ Metallic Bonding
Answer: A system where valence electrons are delocalized in a "sea"
of mobile electrons throughout a lattice of metal nuclei.
◉ What is the best explanation for why metals are ductile?
Answer: Valence electrons act as glue holding nuclei together when
they move relative to one another.
◉ Why is graphite able to conduct electricity while diamond is not?
Answer: Graphite has unhybridized p- orbitals forming a delocalized
pi bonding network for mobile electrons.
◉ What type of bonding is present in BN, the second hardest known
substance?
Answer: A 3D network of covalent bonds
CALCULATIONS WORKBOOK SOLVED
QUESTIONS COMPILATION
◉ What is the trend for atomic radius when moving down a group in
the periodic table?
Answer: The atomic radius increases.
◉ How does ionization energy typically change across a period from
left to right?
Answer: The ionization energy increases
◉ The net positive charge felt by valence electrons after accounting
for shielding is known as ____.
Answer: Effective nuclear charge (Zeff)
◉ According to Coulomb's Law, what is the relationship between the
force of attraction (F) and the distance (r) between charges?
Answer:
◉ Why does a higher effective nuclear charge (Zeff) lead to a smaller
atomic radius?
, Answer: The stronger the positive charge pulls electrons closer to
the nucleus.
◉ What evidence supports the idea that electron energy levels in
atoms are quantized?
Answer: The existence of large, discrete jumps in successive
ionization energies.
◉ Metallic Bonding
Answer: A system where valence electrons are delocalized in a "sea"
of mobile electrons throughout a lattice of metal nuclei.
◉ What is the best explanation for why metals are ductile?
Answer: Valence electrons act as glue holding nuclei together when
they move relative to one another.
◉ Why is graphite able to conduct electricity while diamond is not?
Answer: Graphite has unhybridized p- orbitals forming a delocalized
pi bonding network for mobile electrons.
◉ What type of bonding is present in BN, the second hardest known
substance?
Answer: A 3D network of covalent bonds
