Ionic, Covalent & Metallic Bonding
Atoms form chemical bonds by transferring, sharing, or delocalising outer-shell electrons to achieve a stable electronic configuration. Understanding the differences between ionic, simple molecular covalent, giant covalent, and metallic structures allows you to explain melting points, electrical conductivity, and mechanical properties.
- Ion
- An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
- Covalent Bond
- A chemical bond that involves the sharing of electron pairs between atoms.
- Metallic Bond
- The electrostatic attraction between positive metal ions and delocalised electrons.
Ionic, Covalent & Metallic Bonding: 3D Molecular, Lattice, DNA & Vector Explorer
Drag directly on the 3D model to rotate it through any angle, or switch tabs to inspect VSEPR bond angles, crystal lattices, DNA base pairing, and 3D space diagonals.
Giant Ionic Lattice (Sodium Chloride, NaCl)
- Bonding Type:
- Strong electrostatic attraction between oppositely charged Na⁺ and Cl⁻ ions in all directions
- Melting / Sublimation Point:
- High (801°C): large energy needed to overcome many strong electrostatic attractions
- Electrical Conductivity:
- Insulator when solid (ions fixed in lattice); conducts when molten or aqueous (mobile ions carry charge)
Never write 'delocalised electrons' for an ionic compound. Solid NaCl does not conduct because its ions are locked in fixed positions; melting or dissolving frees the ions to move.
Key Concepts & Exam Definitions (5)
- Ion
- An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
- Covalent Bond
- A chemical bond that involves the sharing of electron pairs between atoms.
- Metallic Bond
- The electrostatic attraction between positive metal ions and delocalised electrons.
- Giant Ionic Lattice
- A regular 3D repeating pattern of alternating positive and negative ions.
- Polymer
- A large molecule made of many small repeating units called monomers, joined by covalent bonds.
Quick-Fire Flashcards (5)
Click any card to check the answer, then mark it as Known to track your progress.
Do ionic compounds conduct electricity?
Give an example of a simple covalent molecule.
What is an alloy?
Why are alloys harder than pure metals?
What type of structure does diamond have?
Exam-Style Questions & Mark Schemes (3)
Write or think through your answer first, then click Check Mark Scheme to see the exact points examiners award marks for.
- Q1
Explain why sodium chloride has a high melting point.
Click “Check Mark Scheme” to compare your answer, It forms a giant ionic lattice with strong electrostatic forces of attraction between oppositely charged ions, which require a lot of energy to overcome.
- Q2
Describe the bonding in a molecule of chlorine (Cl2).
Click “Check Mark Scheme” to compare your answer, Two chlorine atoms share one pair of electrons, forming a single covalent bond.
- Q3
Why does graphite conduct electricity but diamond does not?
Click “Check Mark Scheme” to compare your answer, In graphite, each carbon atom forms only 3 covalent bonds, leaving one delocalised electron per atom that can move and carry charge. Diamond has no delocalised electrons.
Common Exam Questions (3)
What is an ionic bond?
An ionic bond is the strong electrostatic attraction between oppositely charged ions, formed when metal atoms lose outer-shell electrons (forming positive cations) and non-metal atoms gain those electrons (forming negative anions).
How do covalent bonds form?
A covalent bond forms when two non-metal atoms share one or more pairs of outer-shell electrons so that both atoms attain a full outer shell.
Why do metals conduct electricity?
Metals consist of a giant lattice of positive metal ions surrounded by a sea of delocalised outer-shell electrons. Because these delocalised electrons are free to move throughout the structure, they carry electrical charge and thermal energy.
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Electrolysis & Ionic Compounds
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