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Topic Atomic radius
Asked 3 times across 2 UPSC exams over 1 years (2023–2024), peaking in 2023.
Key insights
- Most tested in GEO — 2 of 3 PYQs
- Most asked in 2023
- Recurs across 2 years (2023–2024)
How it travelled across exams
First appearance in each exam — the same idea, reframed.
GEO 2023 → CDS 2024
How the concept evolved
Rising — more than half its appearances (3 of 3) are since 2016.
Related concepts
Ideas UPSC tests alongside this one — keep exploring.
Sample questions
You've seen the pattern — here are a few of the actual PYQs.
CDS2024
The correct order of atomic radius of Li, Na, Be and O is
- A Na > Li > Be > O ✓
- B Na > Be > Li > O
- C Be > Li > Na > O
- D O > Be > Li > Na
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
GEO2023
Which one of the following is the correct order of increase of the atomic radius of the elements?
- A C < B < Si < Al ✓
- B C < B < Al < Si
- C C < Si < B < Al
- D Si < Al < C < B
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
GEO2023
The radius of the first orbit (n =
- of a hydrogen atom is 0·529 Å. Then the radius of the second orbit (n =
- of He⁺ ion will be
- A 1·058 Å ✓
- B 2·116 Å
- C 4·232 Å
- D 0·529 Å
✓ Correct answer: (A)
Science & Technology › Physics & Chemistry
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