Ionic bonding

• an ion is an electrically charged atom formed by the loss or gain of electrons
• the loss or gain of electrons in ions takes place so stye have a full outer shell, which makes the atom more stable
• all metals lose electrons to other atoms to become positively charged ions, known as cations
• all metal ions have positive charges
• all non-metal can gain electrons from other atoms to become negatively charged ions known as anions
• ionic compounds are formed when metal atoms react with non-metal atoms
• the positive and negative ions in ionic compounds are held together by strong electrostatic forces of attraction between opposite charges
• in a dot and cross diagram of ionic compounds:

  • only outer shell electrons are shown
  • the charge of each ion is written in the top right corner
  • multiple ions are shown with a number before the brackets
• ionic compounds have no overall charge, so the positive and negative charges of the individual ions must be balanced
• ionic compounds do not conduct electricity in solid state as ions are not free to move
• ionic compounds do conduct electricity in liquid state or when dissolved in water because the ions are free to move
• ionic compounds have high melting and boiling points
• ionic compounds have a giant lattice structure
• giant lattice structures are held together by strong electrostatic forces between oppositely charged ions
• copper(III) ion - Cu2+
• the charge of iron(II) is Fe2+
• The charge of iron (III) is Fe3+
• the charge of lead is Pb2+
• the charge of Zinc is Zn2+
• The charge of hydrogen is H+
• the charge of ammonium is NH4 +
• a hydroxide ion is OH-
• A carbonate ion is CO3 2-
• A nitrate ion is NO3 -
• a sulfate ion is SO4 2-
• ionic compounds are usually water soluble
• the bonds in the giant ionic lattice structure are very strong, so a lot of energy in needed to overcome them