ICSE Class 10 Chemistry: Chemical Bonding — Important Questions with Answers 2026

Short Answer Questions (2-3 Marks)

• Q: What is a chemical bond? Why do atoms form bonds?
  Ans: A chemical bond is the attractive force that holds atoms together in a molecule or compound. Atoms form bonds to achieve a stable electronic configuration (noble gas configuration — octet/duplet), which is the state of lowest energy.
• Q: Define ionic bond. How is NaCl formed?
  Ans: An ionic (electrovalent) bond is formed by the complete transfer of electrons from a metal atom to a non-metal atom. NaCl formation: Na (2,8,1) loses 1 electron → Na⁺ (2,8). Cl (2,8,7) gains 1 electron → Cl⁻ (2,8,8). Electrostatic attraction between Na⁺ and Cl⁻ forms ionic bond. Electron dot: Na· + ·Cl: → Na⁺[:Cl:]⁻
• Q: Define covalent bond. Explain single, double, and triple bonds with examples.
  Ans: A covalent bond is formed by mutual sharing of electron pairs between two non-metal atoms. Single bond: One shared pair. Example: H₂ (H-H), Cl₂. Double bond: Two shared pairs. Example: O₂ (O=O), CO₂. Triple bond: Three shared pairs. Example: N₂ (N≡N). Bond strength: triple > double > single. Bond length: triple < double < single.

Long Answer / Application Questions (4-6 Marks)

• Q: Compare ionic and covalent compounds (any 4 properties).
  Ans: Ionic compounds: High melting/boiling points, conduct electricity when molten or dissolved, soluble in water, form crystals. Covalent compounds: Low melting/boiling points, do not conduct electricity (no free ions), generally insoluble in water (soluble in organic solvents), exist as molecules.
• Q: What is coordinate bond? Give an example.
  Ans: A coordinate (dative) bond is a type of covalent bond where both shared electrons are donated by one atom (donor) to another atom (acceptor). Example: Formation of ammonium ion (NH₄⁺): NH₃ + H⁺ → NH₄⁺. Nitrogen (donor) has a lone pair which it donates to H⁺ (acceptor). Represented by an arrow (→) from donor to acceptor.

Exam Tips for This Chapter

• Revise all definitions and laws from Chemical Bonding — they are commonly asked as 1-2 mark questions
• Practice diagrams related to Chemical Bonding — neat labelled diagrams carry 2-3 marks
• For numericals, always show formula → substitution → answer with correct units
• Previous year analysis shows Chemical Bonding carries 8-12 marks in the board exam