Charges on Ions

• What is the charge of metal ions?

  Positive
• What is the charge of most non-metal ions?

  Negative
• How are charges on ions related to groups in the periodic table?

  • Metal ions' charges often match their group number
  • Most non-metal ions have negative charges
• What type of ions do metals form?

  Positive ions
• What type of ions do most non-metals form?

  Negative ions
• What is the charge of sodium ion?

  $Na^+$
• What is the charge of magnesium ion?

  $Mg^{2+}$
• What is the charge of aluminium ion?

  $Al^{3+}$
• How does the charge of metal ions relate to their group number in the periodic table?

  • The charge on a metal ion is often the same as its group number
  • Example: Group 1 forms 1+ ions, Group 2 forms 2+ ions, Group 3 forms 3+ ions
• What ions do lithium and potassium form?

  $Li^+$ and $K^+$
• What ions do beryllium and calcium form?

  $Be^{2+}$ and $Ca^{2+}$
• What ions do gallium and indium form?

  $Ga^{3+}$ and $In^{3+}$
• Why do transition metals differ in their ion charges?

  They can form several different ions
• What are the charges of iron ions?

  $Fe^{2+}$ and $Fe^{3+}$
• What are the charges of copper ions?

  $Cu^+$ and $Cu^{2+}$
• What is the charge of the oxide ion?

  $O^{2-}$
• What is the charge of the fluoride ion?

  $F^{-}$
• How do non-metal ions relate to their groups in the periodic table?

  • Non-metals in group 6 form 2- ions (e.g., O^{2-}, S^{2-})
  • Non-metals in group 7 form 1- ions (e.g., F^{-}, Cl^{-}, Br^{-})
• What is the charge of the ammonium ion?

  $NH_4^{+}$
• What is the charge of the hydrogen ion?

  $H^{+}$
• What is unique about hydrogen and ammonium ions compared to other non-metal ions?

  • They are positive ions
  • Most non-metal ions are negative
• What is the formula for sodium sulfate?

  $Na_2SO_4$
• What is the formula for calcium hydroxide?

  $Ca(OH)_2$
• Why is it important to learn how to work out the formulas of ionic compounds?

  • It helps in understanding chemical reactions
  • Essential skill in chemistry
• What should you be able to describe about metal and non-metal ions?

  Metal ions are positive and most non-metal ions are negative
• What is the relationship between ion charges and the periodic table?

  Charges on ions relate to their groups in the periodic table