(40) GCSE Chemistry Revision "Ionic Bonding 2: Ionic Bonding between Group 2 and Group 6"

Understanding Ionic Bonding

Definition of Ionic Bonding

• Ionic bonding occurs when a metal reacts with a non-metal.

• Involves the transfer of electrons from the metal to the non-metal.

• Results in the formation of positively charged ions (cations) and negatively charged ions (anions).

Review of Previous Content

• Previous video illustrated ionic bonding between a Group 1 metal (Lithium) and a Group 7 non-metal (Fluorine).

  • Lithium loses an outer electron to form a Li+ ion.

  • Fluorine gains this electron to form a F- ion.

• Both ions achieve a stable electron configuration similar to that of noble gases.

Ionic Bonding between Group 2 Metals and Group 6 Non-Metals

Example: Magnesium and Oxygen

• Magnesium atom:

  • Contains 12 protons and 12 electrons (neutral atom).

  • Has 2 electrons in its outer energy level.

• Oxygen atom:

  • Contains 8 protons and 8 electrons (neutral atom).

  • Has 6 electrons in its outer energy level.

Reaction Process

• When magnesium reacts with oxygen:

  • Magnesium loses its 2 outer electrons.

  • These 2 electrons are transferred to oxygen.

Resulting Ions

• Magnesium Ion (Mg2+):

  • 12 protons and 10 electrons, resulting in a +2 charge.

• Oxide Ion (O2-):

  • 8 protons and 10 electrons, resulting in a -2 charge.

• Both ions (Mg2+ and O2-) now have a complete outer energy level, achieving stability.

Dot and Cross Diagrams

• Only outer energy levels are illustrated, as they participate in bonding.

• Illustrates the transfer of electrons from magnesium to oxygen.

• Shows the formation of both magnesium ion and oxide ion clearly.

Key Points Recap

• Group 2 metals lose 2 electrons to form +2 ions.

• Group 6 non-metals gain 2 electrons to form -2 ions.

• Both ions end with a full outer energy level, mirroring the noble gas configuration.

Other Examples of Ionic Bonding

• Lithium and Oxygen:

  • Two lithium atoms donate one electron each to one oxygen atom.

  • Results in two Li+ ions and one O2- ion achieving stable configurations.

• Calcium and Fluorine:

  • Calcium loses 2 outer electrons to form a Ca2+ ion.

  • Two fluorine atoms each gain one electron to become two F- ions.

  • All species achieve full outer energy levels post-reaction.

Exam Preparation

• Be prepared to identify and draw ionic bonding reactions between any Group 1 or 2 metals and Group 6 or 7 non-metals.