-Atoms are electrically neutral.
-Number of protons = number of electrons.
-Ions have different number of protons and electrons.
-Ions can be either positive (lost e-) or negative (gained e-)
-Cation = positive ion
-Anion = negative ion
Example 1: Br- : gained 1e-, anion
Chemical Bonds:
-A bond is an electrostatic attraction between particles.
-Bonds occur as elements try to achieve noble gas electron configuration:
1.)Nobel gases (usually) do not form compounds or bonds.
2.)In nobel gases, the outermost energy level have stable octets.
-metals lost elevtrons (oxidize)
-non-metals gain electrons (reduced)
Lewis Dot Structure:
-Atoms can be represented by dot diagrams:
1.)Dots represent electrons.
2.)Only valence electrons are shown.
-Write the atomic symbol for the atom:
1.)This represents the nucleus and filled inner electron levels.
-One dot is used to represent outer energy level electrons:
1.)One e- is placed in each orbital before any pairing occurs.
2.)Beginning with the 5th e-, pairing can occur up to a maximum of 8e-.
Ionic bonds:
-Electrons are transfered from metals to non-metals:
1.)No dots are shown on metal.
-"Charged" species are written in brackets.