CEM 141 Exam 2 (New 2026/ 2027 Update)
Questions & Answers {Grade A} 100%
Correct (Verified Solutions) -MSU
Chemical Reactions - Correct answer Reaction that involves the rearrangements of
valence electrons, the element does not change.
Nuclear Reactions - Correct answer Reaction that involves the nucleus, often results
in change of element, accompanied by mass changes.
Nuclear Fusion - Correct answer Adding two small/light nuclei together to create
more stable element, releases energy, occurs in stars
Ex: Hydrogen burning and helium burning.
Nuclear Fission - Correct answer The fragmentation of heavy nuclei to form light,
more stable nuclei, releases energy
Can become a chain reaction.
,Radioactive Decay - Correct answer Nucleus emits/captures particles of energy in the
form of electromagnetic radiation. a, b, y.
Strong Force - Correct answer Force which holds nucleus together at small distances,
doesn't govern electrons, is attractive for alike and neutral charges.
E = mc2 - Correct answer Binding energy, the energy released when mass is
converted to energy (nuclear reaction).
Emergent Properties - Correct answer When atoms interact to form larger
molecules/structures, like melting/boiling point.
Nanoparticles - Correct answer At the size of 1-100nm, have different properties than
bulk materials, depends on surface area to size ratio.
Why do bonds form? - Correct answer Valence electrons of one atom are attracted to
the nuclei of other atoms.
, Covalent Bond - Correct answer Two hydrogen atoms interact and form this, each
nucleus is attracting both electrons, bond length = most stable, lowest PE, formation
releases energy to surroundings
Strong, hard to predict bond strength, present only when atomic orbitals interact
constructively, within molecules or networks.
Molecular Orbital Theory - Correct answer Combining n atomic orbitals to n molecular
orbitals.
Antibonding Orbitals - Correct answer Atomic orbitals combine destructively to form a
molecular orbital of higher energy, destabilizing, out of phase, creates sigma star
orbital.
Bonding Orbitals - Correct answer Atomic orbitals combine constructively to form a
molecular orbital of lower energy, stabilizing, in phase, creates sigma orbital.
In He-He both boding and antibonding MOs are occupied. Because their energies are
equal and opposite _______. - Correct answer He Doesn't Bond.
Questions & Answers {Grade A} 100%
Correct (Verified Solutions) -MSU
Chemical Reactions - Correct answer Reaction that involves the rearrangements of
valence electrons, the element does not change.
Nuclear Reactions - Correct answer Reaction that involves the nucleus, often results
in change of element, accompanied by mass changes.
Nuclear Fusion - Correct answer Adding two small/light nuclei together to create
more stable element, releases energy, occurs in stars
Ex: Hydrogen burning and helium burning.
Nuclear Fission - Correct answer The fragmentation of heavy nuclei to form light,
more stable nuclei, releases energy
Can become a chain reaction.
,Radioactive Decay - Correct answer Nucleus emits/captures particles of energy in the
form of electromagnetic radiation. a, b, y.
Strong Force - Correct answer Force which holds nucleus together at small distances,
doesn't govern electrons, is attractive for alike and neutral charges.
E = mc2 - Correct answer Binding energy, the energy released when mass is
converted to energy (nuclear reaction).
Emergent Properties - Correct answer When atoms interact to form larger
molecules/structures, like melting/boiling point.
Nanoparticles - Correct answer At the size of 1-100nm, have different properties than
bulk materials, depends on surface area to size ratio.
Why do bonds form? - Correct answer Valence electrons of one atom are attracted to
the nuclei of other atoms.
, Covalent Bond - Correct answer Two hydrogen atoms interact and form this, each
nucleus is attracting both electrons, bond length = most stable, lowest PE, formation
releases energy to surroundings
Strong, hard to predict bond strength, present only when atomic orbitals interact
constructively, within molecules or networks.
Molecular Orbital Theory - Correct answer Combining n atomic orbitals to n molecular
orbitals.
Antibonding Orbitals - Correct answer Atomic orbitals combine destructively to form a
molecular orbital of higher energy, destabilizing, out of phase, creates sigma star
orbital.
Bonding Orbitals - Correct answer Atomic orbitals combine constructively to form a
molecular orbital of lower energy, stabilizing, in phase, creates sigma orbital.
In He-He both boding and antibonding MOs are occupied. Because their energies are
equal and opposite _______. - Correct answer He Doesn't Bond.
