Chapter 6.1
Chapter and Section Review
Key
Section: Compounds and Molecules
Explain what holds compounds
together.
Compounds are
held together by
chemical bonds.
1
Section: Compounds and Molecules
Describe the difference
A ball-and-stick model gives you a
better idea of bond lengths and
bond angles. A space-filling model
gives you a better idea of the
space occupied by atoms.
2
Section: Compounds and Molecules
Explain why adding flexible springs
to the ball and stick model would
make the model more accurate.
The model would be more
accurate because bonds can bend,
stretch, and rotate without
breaking.
3
Section: Compounds and Molecules
Explain why the substance with a
network structure has a high melting
point
Substances with network structures
have strong bonds holding the atoms
or ions together. Much energy (a
higher temperature) is needed to
break these bonds.
4
Section: Compounds and Molecules
Contrast the structure of table
salt and table sugar.
Table salt has a strong network
structure consisting of very
tightly bonded sodium cations
and chloride anions.
5
Section: Compounds and Molecules
Predict whether a compound with a
boiling point of 68 C is likely to be a
network solid or in the form of
individual molecules.
Because the boiling point of the
compound is relatively low, the
compound is likely to be in the
form of individual molecules.
6
Section: Compounds and Molecules
Why do scientists use different types
of models to represent compounds?
Different models show
different traits.
Not every model shows
1
every trait
Section: Compounds and Molecules
Which type of chemical model
shows the bond angle and bond
length between atoms in the
compound?
___________________________
Ball
and stick model
2
Section: Compounds and Molecules
How does this type of model
represent a compound?
Ball = atoms,
stick = bonds
2
Section: Compounds and Molecules
Draw a ball-and-stick model of a boron
trifluoride (BF3)molecule. In this
molecule, three fluorine atoms are
attached to a boron atom. Each F-B-F
bond angle is 120°, and all B-F bonds
are the same length.
X
3
Section: Compounds and Molecules
Explain your answer
The particles in the liquid are
more strongly attracted to one
another than those in the gas
4
Section: Compounds and Molecules
What can you infer about the
attraction between particles in a
substance with a low melting point?
The attraction
between particles is
relatively weak.
5