Ionic Bonding

• Ionic bond

  Bond formed by the transfer of electrons from a metal to a non-metal and is the strong electrostatic force of attraction between oppositely charged ions/between cations and anions in an ionic compound
• Ionic bonding usually occurs between

  metals and non-metals or any cations and anions
• Cation

  positive ion
• Anion

  negative ion
• Do ionic compounds have a fixed formula?

  No, as they exist as giant ionic lattices
• Ionic compounds exist as

  Giant ionic lattices
• What does the formula tell us in an ionic lattice?

  Tells us the ratio of ions in the lattice
• Drawing ionic lattice

  -all ions touching

  -positive ion is smaller

  -negative ion is bigger
• Factors which affect the Strength of ionic compounds

  -charge

  -size
• Ionic bonds are stronger if the positive and/or negative ion is

  -more charged

  -smaller size

  So there are stronger electrostatic forces of attraction between oppositely charged ions
• Properties of ionic compounds

  -high melting point (all are solid at room temperature

  -conduct electricity when molten (l) or in solution (aq)

  -usually soluble in water

  -brittle
• Why do ionic compounds have high melting points?

  They have a giant ionic lattice structure held together by strong electrostatic forces of attraction between oppositely charged ions so a lot of energy is required to overcome these bonds
• Why can ionic compounds conduct electricity when molten (l) or in solution (aq)?

  Because the ions are free to move and carry a current
• Why can't ionic compounds conduct electricity as solids?

  Because the ions are locked in place by strong electrostatic forces of attraction between oppositely charged ions so ions are not free to move and to carry current
• Why are ionic compounds usually soluble in water ?

  Because polar water molecules can attract the positive and negative ions and break apart the lattice. The slightly positive hydrogen attracts anions and the slightly negative oxygen attracts cations. this breaks up the structure.
• Hydroxide ion

  OH-
• Nitrate ion

  NO3-
• Ammonium ion

  NH4+
• Sulfate ion

  SO4 2-
• Carbonate ion

  CO3 2-
• Phosphate ion

  PO4 3-
• Group 1 forms

  1+ ions
• Group 2 forms

  2+ ions
• Group 3 forms

  3+ ions
• Group 5 forms

  3- ions
• Group 6 forms

  2- ions
• Group 7 forms

  1- ions
• Hydride ion

  H-
• Hydrogen Carbonate ion

  HCO3 -
• hydrogen sulfate ion

  HSO4 -
• Silver ion

  Ag+
• Zinc ion

  Zn2+
• Platinum ion

  Pt2+
• Hydrogen ion

  H+
• Why are ionic compounds brittle?

  They are brittle because when the ions are forced out of position, like charges line up and cause repulsion and cracking of the ionic compound
• ______ide

  derived from a single atom
• ________ate

  Derived from a compound where the atom is combined with oxygen