Sodium reacts with chlorine to form sodium chloride. (i) What are the charges on the sodium and chloride ions formed in this reaction? (ii) What force holds these oppositely charged ions together in sodium chloride? (iii) What is the general name for compounds formed by the transfer of electrons between atoms?
Generated by claude-sonnet-4-6 · 2026-06-26 01:03 · grounding rag
Model Answer
(i) Sodium loses one electron to form a sodium cation with a +1 charge (Na⁺), and chlorine gains that electron to form a chloride anion with a −1 charge (Cl⁻).
(ii) The oppositely charged Na⁺ and Cl⁻ ions are held together by a strong electrostatic force of attraction.
(iii) Compounds formed by the transfer of electrons from a metal to a non-metal are called ionic compounds (or electrovalent compounds).
Source: Chapter 3, Section 3.3 – How do Metals and Non-metals React?
---
Explanation
- For (i), always state both charges clearly — examiners check both Na⁺ (+1) and Cl⁻ (−1).
- For (ii), the key phrase is electrostatic forces of attraction — avoid vague terms like "magnetic force."
- For (iii), either "ionic compounds" or "electrovalent compounds" is acceptable; writing both is safest.
- This question tests understanding of electron transfer and ionic bond formation — a frequently asked concept in CBSE board exams.