Types of Chemical Bonding

Overview

• Three main types of bonding:
  • Covalent bonding
  • Ionic bonding
  • Metallic bonding

Covalent Bonding

• Occurs when: Atoms share electrons, causing their outer shells to overlap.
• Happens in: Non-metals only; metals are never involved.
• Types of Covalent Bonding:
  • Simple Covalent: Small molecules with a few atoms (e.g., CH₄, H₂O, CO₂).
    • Most covalent compounds are simple covalent.
  • Giant Covalent: Few exceptions with thousands of atoms (e.g., diamond, graphite, graphene, silicon dioxide).

Characteristics

• Simple Covalent Molecules:
  • Examples: Chlorine (Cl₂), Hydrogen chloride (HCl), Water (H₂O), Oxygen (O₂), Carbon dioxide (CO₂)
  • Characteristics: Few atoms bonded; strong covalent bonds.
• Giant Covalent Structures:
  • Examples: Diamond, Graphite, Graphene, Silicon dioxide
  • Characteristics: Many atoms bonded in large structures.

Practice Questions

1. What is a covalent bond?
2. Which types of elements form covalent bonds?
3. Which compounds have a simple covalent structure?

Ionic Bonding

• Occurs when: Includes both metals and non-metals; involves transfer (gain/loss) of electrons.
• Forms: Giant ionic lattice of positive and negative ions.

Characteristics

• Formation:
  • Metal loses electrons → positive ion.
  • Non-metal gains electrons → negative ion.
  • Attraction between positive and negative ions forms the ionic bond.
• Definition: Strong electrostatic attraction between positive and negative ions.
• Example Compounds: Calcium chloride, Magnesium oxide, Aluminium bromide.

Practice Questions

1. What is an ionic bond?
2. Which types of elements form ionic bonds?
3. Which compounds are ionic?

Metallic Bonding

• Occurs when: Within metals only; non-metals are never involved.

Characteristics

• Formation:
  • Metal atoms lose electrons → positive ions.
  • Electrons become delocalized → form a "sea" of electrons.
  • Attraction between positive ions and delocalized electrons is the metallic bond.
• Definition: Strong electrostatic attraction between positive ions and delocalized electrons.
• Giant Metallic Structure: Thousands of atoms in a lattice form.
• Example Metals: Magnesium, Calcium, Aluminium, Copper, Sodium, Iron.

Practice Questions

1. What is a metallic bond?
2. Which types of elements form metallic bonds?
3. Which compounds are metallic?

Conclusion

• Recap of bonding types and characteristics.
• Importance of understanding different bond types for chemistry studies.

---

Note: Practice questions provided at the end of each section to reinforce understanding.