Chapter 8 – Chemical Bonding
1. Definitions:
- Alkaline earth metals
- Alkali metals
- Halogens
- Nobel gases
- Transition elements
- Stable octet
- Ion
- Ionic compound
- Ionic bond
- Valence electrons
- Molecular compound
- Covalent bond
8.1 Explaining Chemical Families
Copy and Complete the Chart from Page 260. Draw the electron
arrangements for the first 20 Elements. (Hydrogen to Calcium)
HALOGENS
(very reactive)
NOBLE GASES
ALKALI METALS
(very reactive)
ALKALINE
EARTH METALS
(fairly reactive)
2
3
4
9
10
11
12
17
18
19
20
35
36
37
38
53
54
55
56
85
86
87
88
8.2 Ionic Compounds
We will look at the example between Sodium (Na) and Fluorine
(F).
Diagram from Page 26 (Figure 8.7)
One electron has been transferred to fluorine’s outer shell from
sodium’s outer shell. Both atoms now have a stable electron
arrangement. The fluorine atom will be negative in charge and the
sodium atom will be positive in charge due to the loss or gain of
electrons. This is an example of ionic bonding. Ionic bonding
occurs between a metal and a non-metal.
The Formations on Ions
(p. 266-267)
When an atom gains or loses electrons the atom is no longer
neutral. It has become an ion, meaning a particle with a positive
or negative charge. REMEMBER that atoms are neutral until an
exchange occurs. The positive ions and the negative ions attract
each other after the electron re-arrangement occurs. This
between the particles is how ionic bonding takes place. The
attraction is not only strong but it is also in the same directions.
It extends from one ion to the next throughout an ionic
compound. The ions in ionic compounds fit together in a regular
pattern called a crystal lattice.
8.3 Molecular Compounds
Molecular compounds are different than ionic compounds because
they are formed by the sharing of electrons as opposed to the
attraction of charged particles in ionic bonding. This sharing of
electrons is actually very different than ionic bonding in terms of
the type of molecules formed.
An ionic compound behaves like one large structure, with each ion
surrounded by ions of opposite charge. This means that strong
attractions extend throughout the crystal. Most molecular
compounds do not form large structures. Although the bonding
between atoms is strong, the attraction between molecules is
weak.
In a molecule of water, the oxygen atom needs two or more
electrons, so two hydrogen atoms each share a pair of electrons
with the oxygen atom. It is generally the non-metals that are
involved with a co-valent bonding (sharing), while the ionic bonding
involves the metals and non-metal groups.