Ions and Ionic Compounds
How much an element reacts depends on…
Electron Configuration Oxygen vs. Neon
Orbital Diagram for NeonElectron Configuration: 1s22s22p6
Electron Configuration: 1s22s22p4
Oxygen: 2p orbital only has 4 electrons can hold 6 electronsNeon: Has a full 2p electron orbital or shell with 6 electrons
Octet Rule
A concept of chemical bonding theory that atoms tend to have either an empty valence shell or full valence shell of 8 electrons. All atoms try to get an octet, 8 electrons in their outermost shell by either losing or gaining electrons. This is an attempt to have the electron configuration of a noble gas.*Valence shell: the electrons found in the
outermost shell of an atom.Orbital Electrons
s 2
p 6
d 10
f 14
Alkali Metals and Halogens Most reactive elements Outer s and p orbital that do not match the
Noble gases will react to lose or gain an electron…so the outer orbital will be full.
Cations and Anions
Cation: atoms lose electrons Usually metals
Anion: atom gains electrons Usually non-metals
Ions form in order to achieve an octet (or as close as possible).
Ions have different properties than their parent atoms.
Oxidation states, valences
Ion examples
Order of Stability
Octet
Filled or half filled outer orbital
Fill the best they can
Ionic Bonding and Salts Ionic bond: transfer of electrons (opposite
charges attract, cations and anions) compound becomes electroneutral (+ = - no net charge)
Sodium Chloride
Ionic bond form between sodium cations and chloride anions
Electrostatic attraction crystals
Ionic compounds
Do not consist of molecules Bonds are strong,multiple attractions
High melting point and boiling point Hard and Brittle Conduct electricity (if ions are mobile, in
other words melted or dissolved in water)
Conducting electricity
Crystals
Crystal lattice: regular pattern in which a crystal is arranged
Unit cell: the smallest portion of a crystal lattice that shows a 3-d pattern of the entire lattice
Some examples of unit cells