Atoms V.S ions

- Atoms are electrically neutral
- # of protons = # of electrons
- Ions have a different number of protons and electrons
- Ions can either be positve (lose electrons) or negative (gain electrons)
- Cation = positive ion
- Anion = Negative ion
Here is a video about Atoms V.S Ions










Chemical Bonds - A bond is an electrostatic attraction between particles
- Bonds occur as elements try to achieve Noble gas electron configuration
- Noble gases (usually) do not form compounds or bonds
- In Noble gases the outermost energy levels have stable octets

Lewis Dot Structures - Atoms can be represented by dot diagrams - Dots represent electrons - Only valence electrons are shown - Write the atomic symbol for the atom - This represents the nucleus and filled inner energy levels - One dot is used to represent outer energy levles - One e- is placed in each orbital before any pairing occurs - Beginning with the 5th e-, pairing can occur up to a maximum of 8e- - Below: Electron dot diagrams for water

Ionic Bonds
- Electrons are transferred from metal to non-metal
- No dots are shown on metal
- "Charged" species are written in brackets

Here is a video about how to draw a dot diagram