Atoms & Ions

- Atoms are electrically neutral
- # of protons = # of electrons
- Ions have different # of protons and electrons
- Ions can be either positive (lose e) or negative (gain e)
- cation = positive ion
- anion = negative ion

Example:
C4-
Carbon gains 4 electrons and it is an anion.

CHEMICAL BONDS
- A bond is an electrostatic attraction between particles.
- Bonds occur as elements try to achieve Noble gas electron configuration
- Noble gases (usually) don't form compounds or bonds
- In Noble gases, the outermost energy level have stable octects.
- Metals lose electrons (oxidize)
- Non-metals gain electrons (reduced)

LEWIS DOT STRUCTURE
- Atoms can be represented by dot diagrams
- Dots represent electrons
- Only valeance level electrons are shown
- The atomic symbol for the atom represents the nucleus and filled inner electron levels
- One dot is used to represent outer energy level electrons

** Some helpful info:
http://www.ausetute.com.au/lewisstr.html



IONIC BONDS
- Electrons are transferred from metal to non-metal
- No dots are shown on metal
- 'Charged' species is written in brackets

Na + Cl → Na⁺ + Cl⁻ → NaCl