Gidemy

1. Ionic (Electrovalent) Bonding

• Ionic bonding is the transfer of electrons from one atom to another to achieve an inert gas electron configuration, forming ions. It is an electrostatic attraction between oppositely charged ions.
• Ionic bonds are formed between METALLIC and NON- METALLIC ATOMS ONLY.  During ionic bonding
  • Metals lose electrons to form positive ions (cations)
  • Non-metals gain electrons to form negative ions (anions)
• The formation of ions is resulted from the transfer of atoms from one atom to another atom(s), producing ions of opposite charges, and unlike charges attract, causing them to be held together with a strong force.
• The following diagram shows ionic bonding between magnesium and flourine to form Magnesium Flouride (MgF₂)

• Sodium atom loses two electrons by transferring the electrons to fluorine atoms, one each, making both stable. The loss of electron forms cation, Mg²⁺, as it loses 2 electrons, and the gain of electron forms anion, F ^– .
• The opposite charges acquired by both ions attract to each other, forming a strong ionic bond of MgF₂.

Properties of Ionic Compounds

• The following are the properties of ionic compounds.
• They are hard crystalline solids with flat sides and regular shapes because the ions are arranged in straight rows in strong ionic bonds
• They have very high melting points and boiling points.
• They do not evaporate esealy because of the strong forces holding themn together.
• They have no smell because of not evaporating easily.
• They don’t conduct electricity but do conduct when they are in in aqueous or molten form. This is because in liquid/aqueous state the ions which conduct electricity are free to move. In solids, these ions are fixed in place.
• They are soluble in water but insoluble in organic compounds. This is because the ions attract water molecules which distrupts the crystal structure, causing them to separate & go into solution.  But in organic solvent the ions do not attract to the solvent molecules because they have no charge.

Uses of Ionic Compounds

Ionic compounds have long had a wide variety of uses and applications. Many minerals are ionic. Humans have processed sodium chloride an ionic compound for over 8000 years, using it first as a food seasoning and preservative, and now also in manufacturing, agriculture, water conditioning, and de-icing roads.

Assignment

1. Explain the use of ionic compounds as refractory materials for ionic