Chemical Bonds & Intermolecular Forces

Chemical Bonds

Occurs between metals and non-metals.
Involves the transfer of electrons in outer shells.
Metals lose electrons to form positive ions; non-metals gain electrons to form negative ions.
Electrostatic attraction between oppositely charged ions is ionic bonding.
Ions formed by Group 1 and 2 metals, and Group 6 and 7 non-metals relate to their group number.
- Group 1 forms 1+ ions, Group 2 forms 2+ ions, Group 6 forms 2- ions, Group 7 forms 1- ions.
Ionic compounds have giant structures held together by strong electrostatic forces in all directions.
Empirical formula: Simplest ratio of ions in the giant structure (e.g., NaCl).

Atoms share pairs of electrons to form strong covalent bonds.
Covalently bonded substances can be small molecules, large molecules (polymers), or giant covalent structures.
Limitations of dot and cross diagrams:
- Electrons shown differently, but they are the same.
- Doesn't accurately show bond angles or molecular shape.

Electrons in outer shells of metal atoms are delocalized and free to move.
Sharing of delocalized electrons creates strong metallic bonds.
Metals have a giant structure with atoms in regular patterns.
Atoms are arranged neatly in rows surrounded by a "sea" of delocalized electrons.
Metal atoms lose outer shell electrons, resulting in more protons than electrons, thus becoming positively charged.