BONDING

Bonds Between Atoms

Covalent

Ionic

MoleculesNetwork

Metallic

Metallic Bonding

Metals lose their outer electrons easily and become cations

creating a “sea” of electrons to roam freely around the metal cations.

The strong electrostatic attraction between cations and roaming electrons explains why:

• metals conduct electricity• are extremely strong and

hard to break• Can be bent and stretched• Have high melting points

Malleable and Ductile

The mobile electrons will shift to adjust to new arrangements around positive ions. They act as the "glue".

Ionic Bonding

Ionic Bonds

- results from the TRANSFER of electrons from a metal to a non-metal

Ions are held strongly by electrostatic forces in a 3D lattice

Properties

1.Have high melting points because of strong electrostatic attractions between cations and anions

2.Soluble in water

3. Conducts electricity if dissolved in water (has free ions) but not in solid state

4. Brittle – similar ions can repel when disturbed

Covalent Molecules

Covalent Molecular

- When 2 or more non-metals SHARE electrons; no charged ions are formed

- Does NOT form large lattices

- forms small, neutral molecules that are weakly attracted to other molecules

Forces

Properties:

1.Weak forces between molecules means that it has low melting points.

2.Does not conduct electrical current

Covalent Network

Covalent Network Solids

•when either carbon or silicon atoms are bonded covalently to form an infinite 3-D lattice

•network solids are extraordinarily strong

Diamond

•Each Carbon atom bonds to 4 others

•Strong covalent bonds throughout

•High melting points

•does not conduct electricity.

Silicon Dioxide: Sand & Quartz

• SiO2