Summary
Covalent bonding involves the sharing of electrons between non-metal atoms to achieve a full outer shell of electrons. This type of bonding results in the formation of molecules with strong covalent bonds between atoms and weak intermolecular forces between molecules.
- Covalent Bond — a bond formed when atoms share pairs of electrons. Example: Water (H₂O) has covalent bonds between hydrogen and oxygen atoms.
- Molecule — a group of atoms bonded together by covalent bonds. Example: A molecule of carbon dioxide (CO₂) consists of one carbon atom double-bonded to two oxygen atoms.
- Intermolecular Forces — weak forces of attraction between molecules. Example: The weak forces between water molecules that allow it to be a liquid at room temperature.
Exam Tips
Key Definitions to Remember
- Covalent Bond: A bond formed by the sharing of electrons between atoms.
- Molecule: A group of atoms bonded together by covalent bonds.
Common Confusions
- Confusing covalent bonds with ionic bonds, which involve the transfer of electrons.
- Assuming covalent compounds conduct electricity; they generally do not.
Typical Exam Questions
- What is a covalent bond? A covalent bond is formed when atoms share pairs of electrons.
- Why do covalent compounds generally have low melting points? Because they have weak intermolecular forces between molecules.
- Do covalent compounds conduct electricity? No, they do not conduct electricity as they lack free electrons or ions.
What Examiners Usually Test
- Understanding of how covalent bonds form between non-metal atoms.
- Ability to identify examples of covalent compounds.
- Knowledge of the properties of covalent compounds, such as melting points and electrical conductivity.