Match Column-I with Column-II Choose the correct option:

Question

Match Column-I with Column-II

Choose the correct option:

1. A. i-c, ii-b, iii-a, iv-d (Correct answer)
2. B. i-b, ii-c, iii-a, iv-d
3. C. i-b, ii-c, iii-d, iv-a
4. D. i-c, ii-b, iii-d, iv-a

Correct Answer

Option A — i-c, ii-b, iii-a, iv-d

Detailed Solution & Explanation

The correct answer is i-c, ii-b, iii-a, iv-d.

Key Points

• The correct matching is:

• Cesium melts at about 28.5 °C — it liquefies in the hand. Along with gallium (29.8 °C), mercury (−39 °C) and francium, it is an exception to the rule that metals have high melting points.
• Zinc is brittle at room temperature and shatters when hammered, unlike most metals which are malleable. (It becomes malleable between 100 °C and 150 °C.)
• Iodine is a lustrous non-metal, forming shiny greyish-black crystals with a metallic sheen — the standard exception to "non-metals are dull".
• Graphite is the non-metal that conducts electricity, because each carbon atom bonds to only three others, leaving one delocalised electron free to move.

Additional Information

• The four classic exceptions in this chapter, all frequently examined:
  • Metals that are not solid: mercury is liquid at room temperature.
  • Metals that are not hard: sodium and potassium can be cut with a knife.
  • Non-metals that are lustrous: iodine, and graphite.
  • Non-metals that conduct: graphite (electricity), and diamond (heat, being the best known thermal conductor).
• Graphite's structure: hexagonal layers held together by weak van der Waals forces, which is why it is soft and slippery and is used as a lubricant and in pencil leads. Diamond, with all four bonds used in a rigid tetrahedral network, is the hardest natural substance and an electrical insulator — both are allotropes of carbon.