5.1 Review an Reinforce
Atoms, Bonding, and
the Periodic Table
1. 7
2. 7
3. 5
4. It is reactive because it needs three valence
electrons to become stable.
5. Nonmetal
6. Valence electrons have the highest energy
and are most loosely held by the atom
7. chemical bond
8. Electrons may be transferred or shared
between atoms.
9. If atoms of an element have less than eight
valence electrons, the element will likely react
with other elements.
10. the same number of valence electrons
11. lose
12. gain; share
5.2 Review and Reinforce
Ionic Bonds
1.
An atom becomes a positive ion by losing
an electron. An atom becomes a negative ion by
gaining an electron.
2.
Oppositely charged ions are attracted to
each other. When ionic bonds form, the ions
come together in a way that balances out the
charges on the ions.
3.
Solid ionic compounds typically form hard,
brittle crystals and have high melting points.
They conduct electricity well when dissolved in
water or melted.
4.
As solids, the ions are tightly bound in ionic
bonds. The ions are free to move when the
compound is dissolved in water. Then electricity
can flow.
5.
Two. A sulfide ion has a charge of 2
. Since
potassium ions only have a charge of 1+, two
potassium ions are needed to balance the
charge.
6.
CaCl
2
,K
3
PO
4
7.
Magnesium sulfide, ammonium chloride,
and potassium oxide
8.
Ammonium and phosphate are polyatomic.
9.
An atom or group of atoms that has an
electrical charge
10.
The attraction between oppositely
charged ions
11.
In a crystal, positive and negative ions
alternate, forming an orderly three-dimensional
arrangement.
5.3 Review and Reinforce
Covalent Bonds
1.
Students should have drawn one circle
around the shared electrons in each diagram
(two electron pairs shared in O
2
and three pairs
in N
2
).
2.
The bond in O
2
3.
The bond in N
2
4.
N
2
,O
2
, and F
2
have nonpolar bonds.
5.
The polar bond is a result of the fluorine
atom pulling more strongly on the shared electrons
than the hydrogen atom.
6.
Compared to ionic compounds, molecular
compounds have lower melting and boiling
points. Most molecular compounds are poor
conductors of electricity when melted or
dissolved.
7.
nonpolar
8.
polar
9.
polar
10.
Nonpolar
5.4 Review and Reinforce
Bonding in Metals
1. Ability to conduct heat and electricity,
ability to change shape easily, and luster
2. An alloy is a mixture made of two or more
elements that has the properties of metal.
3. Alloys can be harder and less likely to react
with air and water than pure metals.
4. metallic bond
5. Point a represents positively charged metal
ions. Point b represents freely moving valence
electrons.
6. Striking or hammering a metal to make it
change shape
7. In metallic bonding, metal ions are
attracted to the freely moving electrons all
around them and not to other metal ions. The
ions can be pushed away from one another, but
the metallic bonds hold the ions close enough
together so that the metal does not break.