● Positive ion = Cation
● Negative ion = Anion
Ionic bonding
● The electrostatic forces of attraction between oppositely charged ions
● Formed via the transfer of electrons between metals and nonmetals
● Ionic compounds form salts
● Transition metals have complex electron arrangement so they can
form more than one type of ion
- An electronegativity difference of 1.7 and up means the bond is ionic
Ionic compounds structure
● Forces of electrostatic attraction between ions cause ions to surround
themselves with ions of opposite charge, forming a three-dimensional
crystalline
Ionic compounds properties
Melting + Boiling point
● Electrostatic force of attraction between ions is very strong hence
large amounts of energy is required to break the ionic bond = high
melting + boiling point
● Solid at room temperature
● Melting point + Boiling point increase with charge due to greater
attraction between the ions
Volatility: Tendency for a substance to vaporize
● Low volatility/non-volatile
Conductivity
● Non conductive in solid state because there are no moveable ions or
delocalized electrons
● Conductive in aqueous + liquid state
, Metallic bonding
● The electrostatic force of attraction between the positive metal ions
and their delocalized electrons
● Strength of metallic bond depends on the charge of the ions and the
ionic radius
● Strength of metallic bond decreases down a group
Metallic structures
● Giant lattice structure (3D of cations, sea of delocalized electrons)
Metal alloys
● Alloys: Solution of solid metals
● Produce by adding one metal to another in the molten state
● Alloys are typically harder than the original metal because there are
different sized atoms that restrict amount of pressure that can be
applied
● Bonds are directional = layers cannot slide
● Alloys have delocalized electrons
Covalent bonding
● The electrostatic force of attraction between the positive nuclei and
the shared pair of electrons
● Formation of covalent bond stabilizes the atom as energy is released
● An electronegativity difference between 0-0.4 means the bond is
nonpolar covalent, 0.4-1.7 means the bond is polar covalent
- coordinate bond/dative covalent bond: An electron pair covalent bond
that is donated from one of the atoms (Ligands)