Chapters 1 - / All Chapters with Answers
and Rationals
Elements in the same period of the periodic table are similar in ___________. - ANSWER: size
Elements in the same group of the periodic table have similar _______________ and
_______________ properties. - ANSWER: chemical, electrical
An s-orbital is ______________ in energy than other orbitals of the same shell, due to e- density
remaining closer to the nucleus. - ANSWER: lower
A p-orbital contains a __________ of e- density at the nucleus and is also _____________ in energy
than an s-orbital (in the same shell), due to e- density residing farther away from the nucleus. -
ANSWER: node, higher
Bonding is a favorable process because it always leads to ______________ energy and
________________ stability between two or more elements. - ANSWER: lowered, increased
A ______________ may have either ionic or covalent bonds. - ANSWER: compound
A _______________ has only covalent bonds. - ANSWER: molecule
_____________ are different molecules; same molecular formula but different in connectivity. -
ANSWER: Isomers
-constitutional isomers same molecular formula differ in connectivity; stereoisomers same molecular
formula differ in spatial arrangement
Exception to the octet rule: Elements in groups 2A and 3A, such as ___________ and __________, do
not have enough valence e- to form an octet in a neutral molecule; thus, they can each have
__________ than eight e- around them. - ANSWER: beryllium, boron, less than eight e- around them
-ex.) BeH2, BF3
A second exception to the octet rule occurs with some elements located in the third row and later in
the periodic table; empty _____ -orbitals available to accept e-; thus, they may have _________ than
eight e- around them. _____________ and _____________ are common elements in this category. -
ANSWER: d-orbitals, more than eight e- around them, phosphorus and sulfur
__________________ structures are two Lewis structures having the same placement of atoms but a
different arrangement of e- (same connectivity, but differ in position of e-). - ANSWER: Resonance
structures
The composite of two or more resonance forms is called a resonance _________ and represents the
true structure of a molecule. - ANSWER: resonance hybrid
Resonance allows certain e- pairs to be _______________ over two or more atoms and this adds
_____________ to the molecule. - ANSWER: delocalized, stability
-delocalization of e- density adds stability
A molecule with two or more resonance structures is said to be _____________ ________________. -
ANSWER: resonance stabilized