Study Notes
Simple molecules are formed when non-metallic elements share electrons to achieve noble gas configurations through covalent bonds. These molecules have properties like low melting and boiling points and poor electrical conductivity due to weak intermolecular forces.
- Covalent Bond — a bond formed when a pair of electrons is shared between two atoms. Example: HCl
- Simple Molecule — a molecule consisting of a small number of atoms bonded covalently. Example: H2O
- Intermolecular Forces — weak forces between molecules affecting their physical properties. Example: Low boiling point of CH4
Exam Tips
Key Definitions to Remember
- Covalent Bond
- Simple Molecule
- Intermolecular Forces
Common Confusions
- Confusing covalent bonds with ionic bonds
- Misunderstanding the role of intermolecular forces in boiling points
Typical Exam Questions
- What is a covalent bond? A covalent bond is the sharing of a pair of electrons between two atoms.
- Why do simple molecular compounds have low melting points? They have low melting points due to weak intermolecular forces.
- How do you represent a covalent bond in a dot-and-cross diagram? Show the shared pair of electrons between the atoms.
What Examiners Usually Test
- Ability to draw dot-and-cross diagrams
- Understanding of properties of simple molecular compounds
- Differences between covalent and ionic bonding