JEE Main 2021 · 18 March · evening · Single correct · +4 / −1
Match List - I with List - II :
Choose the most appropriate answer from the option given below :
| List - I | List - II | ||
|---|---|---|---|
| (a) | Be | (i) | treatment of cancer |
| (b) | Mg | (ii) | extraction of metals |
| (c) | Ca | (iii) | incendiary bombs and signals |
| (d) | Ra | (iv) | windows of X-ray tubes |
| (v) | bearings for motor engines |
- (a) (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
- (b) (a)-(iii), (b)-(iv), (c)-(v), (d)-(ii)
- (c) (a)-(iii), (b)-(iv), (c)-(ii), (d)-(v)
- (d) (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
Answer and solution
Answer (d) (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
Solution
Chemistry ma’am · 3 steps
Match each metal by the property that makes it useful, and each list item falls into place.
- Link use to property. Each use in List II comes from one special property of the metal: how light it is, how it burns, how easily it gives up electrons, or whether it is radioactive.
Metal Key property Use Be Very low atomic number, so it hardly absorbs X-rays (iv) windows of X-ray tubes Mg Burns with a dazzling white flame (iii) incendiary bombs and signals Ca Strong reducing agent; removes oxygen from oxides that carbon cannot reduce (ii) extraction of metals Ra Radioactive; its radiation destroys cancer cells (i) treatment of cancer - The extra item. Item (v), bearings for motor engines, is a distractor. It is not the standard textbook use of any of these four metals, so it is left unmatched.
- So. The matching is (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i), which is option (d).
The idea to keep. For s-block uses, always ask which property is at work: light Be lets X-rays through, Mg burns brilliantly, Ca reduces stubborn oxides, and radioactive Ra treats cancer.
Answer from the NTA final answer key. Solution by PrepWiser.