ionic bonding

• What type of bond is formed when particles bond together through ionic bonds?

  Ionic bonds
• What are ions formed from?

  Ions are formed when atoms lose or gain electrons
• How does a sodium atom become a sodium ion?

  A sodium atom loses one electron to form a sodium one plus ion
• Why does a sodium atom need to lose an electron?

  To achieve stability by having a full outer shell
• What does chlorine need to do to form a chloride ion?

  Chlorine needs to gain one electron
• What happens to sodium and chlorine after the transfer of electrons?

  Both become ions with full outer shells of electrons
• How are ions represented in diagrams?


  With square brackets around them and their charge in the top right corner
• What is the nature of the force that attracts oppositely charged ions?

  It is called an ionic bond
• How does the strength of ionic bonds compare to covalent bonds?

  Ionic bonds are similar in strength to covalent bonds
• What is a dot and cross diagram used for?

  To represent the bonding of atoms
• How are electrons represented in a dot and cross diagram?

  Electrons of one atom are shown as dots and those of another as crosses
• What should you show to indicate the movement of electrons in a dot and cross diagram?

  You should show the movement of electrons with an arrow
• What is typically shown in a dot and cross diagram?

  Every electron shell of the atoms
• In a simplified dot and cross diagram, what is often drawn?

  Only the outermost shell of the atoms
• How do you draw the dot and cross diagram for magnesium chloride (MgCl₂)?

  1. Draw magnesium with two outer electrons.
  2. Draw two chlorine atoms, each with seven outer electrons.
  3. Show the transfer of electrons from magnesium to each chlorine.
  4. Resulting ions: magnesium two plus ion and two chloride one minus ions.
  5. Arrange ions as they would be in a real compound.
• What happens to magnesium when it forms an ion?

  Magnesium loses two electrons to form a magnesium two plus ion
• How do the chloride ions relate to the magnesium ion in the compound?

  The chloride ions are attracted to the positive magnesium ion
• How many chloride ions are formed from one magnesium ion in magnesium chloride?

  Two chloride ions
• What is the final arrangement of ions in a dot and cross diagram for magnesium chloride?

  The chloride ions are placed on either side of the magnesium ion
• What are the key features of a dot and cross diagram?

  • Electrons of one atom as dots, the other as crosses
  • Movement of electrons shown with arrows
  • Can show all electron shells or just the outermost shell
  • Ions arranged as they would be in a real compound