Free Science Lessons: Ionic Compounds

Objectives

• Learn to draw dot and cross diagrams for the formation of ionic compounds.

Key Concepts

Ionic Compounds

• Examples: Sodium chloride (NaCl) and magnesium oxide (MgO).
• Formed by the reaction of metals and non-metals.

Electron Configuration

• Sodium (Na): Metal with outer shell electrons can achieve noble gas configuration (Neon) by losing one electron.
• Chlorine (Cl): Non-metal can achieve noble gas configuration (Argon) by gaining one electron.

Ionic Bonding Process

• Electron Transfer: From metal to non-metal.
  • Sodium loses one electron to form Na⁺ ion (positive charge).
  • Chlorine gains one electron to form Cl⁻ ion (negative charge).
• Resulting Ions:
  • Sodium ion (Na⁺) has the same electron configuration as Neon.
  • Chloride ion (Cl⁻) has the same electron configuration as Argon.
• Electrostatic Attraction: Positive and negative ions are attracted by electrostatic forces.

Practice Example

Magnesium and Oxygen

• Magnesium (Mg): Loses two electrons.
• Oxygen (O): Gains two electrons.
• Resulting Ions: Both Mg²⁺ and O²⁻ ions have the electron configuration of Neon.

Important Points

• Square Brackets: Indicate the charge is spread over the whole ion.
• Noble Gas Configuration: Achieving stability by having the same electron arrangement as noble gases.

Next Steps

• Learn how ions form a giant ionic lattice.
• Understand the physical properties of ionic compounds in the next video.