Atoms bond chemically to form
molecules.
Types of bonding
The periodic table is organized in columns, called groups or
families, and rows, called periods. There are several groups or
periods that have specific names.
| Bond type
|
Happens between |
Electrons are |
| Ionic |
Metal & non-metal |
Transferred |
| Covalent |
Non-metals |
Shared |
| Polar Covalent |
Non-metals |
Shared unevenly |
| Metallic |
Metals |
pooled |
There are general characteristics of each type of
bonding:
- Ionic: High melting points, most
dissolve in water, conduct electricity when dissolved in
water, brittle
- Covalent: Low melting points, most do
not dissolve in water, do not conduct electricity when
dissolved in water
- Polar covalent: Medium melting points,
some dissolve in water, do not conduct electricity when
dissolved in water
- Metallic: Soft, conduct heat and
electricity, do not dissolve in water
Bond Polarity
When nonmetals bond covalently with a large difference in
electronegativity, a polar bond is formed. A polar bond has a
partial separation of charges. Polar bonds are symbolized with an
arrow pointing towards the more electronegative element and a
crossed tail by the less electronegative element
Valence Shell Bonding Theory
The Valence Shell Bonding Theory assumes that bonds
are formed when atomic orbitals overlap. Direct overlap leads to
sigma bonds and parallel overlap leads to pi bond.
