Ionic compounds

• What is an ion?

  An ion is an atom or group of atoms with a positive or negative charge.
• How do ions form?

  Ions form when atoms lose or gain electrons to obtain a full outer shell.
• What happens to metal atoms when they form ions?

  Metal atoms lose electrons to form positively charged ions.
• Why are the ions formed from metal atoms positively charged?

  They are positively charged because they have more protons than electrons.
• What electronic structure do ions formed from metal atoms have?

  They have the electronic structure of a noble gas with a full outer shell.
• How many electrons do elements in groups 1, 2, and 3 lose when forming ions?

  The number of electrons lost is the same as the group number.
• What ion does a sodium atom form when it loses one electron?

  A sodium ion, represented as Na⁺.
• What happens to non-metal atoms when they form ions?

  Non-metal atoms gain electrons to form negatively charged ions.
• Why are the ions formed from non-metal atoms negatively charged?

  They are negatively charged because they have more electrons than protons.
• What is the charge on ions formed from elements in groups 6 and 7?

  The charge is equal to (8 minus the group number).
• What is the charge on sulfur ions, which is in group 6?

  The charge is negative, and it is -2.
• What is an ionic compound made of?

  • Charged particles called ions
  • Has a giant lattice structure
  • Strong electrostatic forces of attraction
• How do positive and negative ions form ionic bonds?

  They form by transferring electrons from a metal to a non-metal.
• What is a dot and cross diagram used for?

  It models the transfer of electrons from metal atoms to non-metal atoms.
• What does the ionic lattice represent?

  It represents a giant structure of ions with a regular, repeating arrangement.
• How many ions can a single grain of salt contain?

  A single grain of salt may contain approximately $1.2 \times 10^{18}$ ions.
• What holds an ionic lattice together?

  Strong electrostatic forces of attraction between oppositely charged ions.
• What are the properties of ionic compounds?

  • High melting points
  • High boiling points
  • Conduct electricity when melted or in solution
  • Insulators when solid
• Why do ionic compounds have high melting and boiling points?

  Because a lot of energy is needed to overcome the strong electrostatic forces of attraction.
• What is the melting point of NaCl?

  801°C
• What is the boiling point of MgO?

  3,600°C
• How does the charge on ions affect the strength of ionic bonds?

  Ions with higher charge have stronger forces and require more energy to overcome.
• When can ionic compounds conduct electricity?

  When they are melted or dissolved in water to form an aqueous solution.
• Why can't ionic compounds conduct electricity in the solid state?

  Because their ions are held in fixed positions and cannot move.
• What is the key fact about ionic compounds and electricity?

  Ionic compounds conduct electricity when melted or in solution, and are insulators when solid.