ICSE Class 10Chemistry
⏱️ 14 min readChemical Bonding – Ionic and Covalent
Electrovalent bonds: Complete transfer of valence electrons forming electrostatic crystal lattices.; Covalent bonds: Mutual sharing of pairs between non-metals to complete octet/duplet.
⚡ Essential Formula / LawCore Syllabus Rule
ΔEN > 1.7 → Predominantly Ionic | 0.4 ≤ ΔEN ≤ 1.7 → Polar Covalent | ΔEN < 0.4 → Non-Polar
🎯 High-Yield Syllabus Checkpoints
- 1Electrovalent bonds: Complete transfer of valence electrons forming electrostatic crystal lattices.
- 2Covalent bonds: Mutual sharing of pairs between non-metals to complete octet/duplet.
- 3Coordinate (Dative) bond: Both shared electrons supplied exclusively by one donor atom (e.g. NH₄⁺, H₃O⁺).
🚨 Examiner Traps & Common Mistakes
⚠️ Common Student Pitfall
Claiming NH₄⁺ has four coordinate bonds (it has three covalent N-H bonds and ONE coordinate bond).
⚠️ Common Student Pitfall
Drawing electron dot diagrams without showing before-and-after states with ionic charges.
📚 Verified Technical Definitions
Coordinate Bond
A type of covalent bond in which both the shared electrons are provided by only one of the participating atoms.
Polar Covalent Molecule
A covalent molecule having fractional charge separation due to unequal electronegativity between bonded atoms (e.g. HCl, H₂O).
Spaced Repetition Protocol:
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