Summary
Ions are atoms or groups of atoms with a positive or negative charge, formed by losing or gaining electrons. Ionic bonds are strong electrostatic attractions between oppositely charged ions, typically formed between metals and non-metals.
- Ion — an atom or group of atoms with a positive or negative charge Example: Sodium (Na) loses one electron to form Na+
- Cation — positive ion formed when an atom loses electrons Example: Sodium (Na) loses one electron to form Na+
- Anion — negative ion formed when an atom gains electrons Example: Chlorine (Cl) gains one electron to form Cl-
- Ionic Bond — strong electrostatic attraction between oppositely charged ions Example: Sodium Chloride (NaCl) is formed by the transfer of electrons from sodium to chlorine
- Lattice Structure — regular arrangement of ions in an ionic compound held together by electrostatic forces Example: The lattice structure of NaCl requires a lot of energy to overcome
Exam Tips
Key Definitions to Remember
- Ion: An atom or group of atoms with a charge
- Cation: A positive ion formed by losing electrons
- Anion: A negative ion formed by gaining electrons
- Ionic Bond: Electrostatic attraction between oppositely charged ions
Common Confusions
- Confusing cations and anions: Remember cations are positive and anions are negative
- Misunderstanding ionic and covalent bonds: Ionic bonds involve transfer of electrons, while covalent bonds involve sharing
Typical Exam Questions
- What is an ion? An atom or group of atoms with a positive or negative charge
- How is an ionic bond formed? Through the transfer of electrons from one atom to another, creating oppositely charged ions
- What is the structure of ionic compounds? A lattice structure of alternating positive and negative ions
What Examiners Usually Test
- Understanding of how ions form
- Ability to explain ionic bonding
- Knowledge of the properties of ionic compounds