Acme Ai
A
अ
GS Paper IUPSC Prelims 1997
Health & Medicine
Question No. 341Interactive Test Mode
00:00
+2-0.66

Q341. The most reactive among the halogens is:

The most reactive among the halogens is:

Select the correct option below (or cross out options to eliminate)
PrevNext Question

Official Answer Key & Detailed Solution

3D PYQ Realm

Ready to check the official UPSC Answer Key?

Click any option above to test yourself under exam conditions, or reveal the explanation directly.

Official UPSC Answer KeyUPSC Prelims 1997 • Science and Technology

Correct Answer: Option (A) — Fluorine

Concept & Option Breakdown

Standard Reference Verified

Fluorine is the most reactive halogen due to its highest electronegativity, smallest atomic radius (which enables strong attraction for incoming electrons), and exceptionally low bond dissociation energy of the $F-F$ single bond caused by lone-pair repulsions.

Elimination Heuristic & Exam Approach

In Group 17 (halogens), chemical reactivity decreases down the group ($F_2 > Cl_2 > Br_2 > I_2$). Hence, Fluorine at the top is the most reactive.

Reviewed by Avinash Sir & Acme AI Research Team

Practice Full-Length & Sectional Prelims Mocks on this Interface

50 simulated tests in the APT Prelims Test Series (₹1,493) or 1-on-1 Mentorship with Avinash Sir.

1-on-1 MentorshipOpen Test Platform

Question Specifications & Syllabus Mapping

Examination & YearUPSC Civil Services Preliminary Examination 1997 (Q341)
Paper & Marking SchemeGS Paper I • 2 Marks (-0.66 Negative for incorrect response)
Syllabus Subject & TopicScience and Technology → Health & Medicine
Official Answer KeyOption (A) — Fluorine

More PYQs from Science and Technology (Health & Medicine)

Master the Science and Technology syllabus cluster by practicing these related previous year questions.

View All Science and Technology PYQs
1998 • Q340Health & Medicine

Assertion (A): Sodium metal is stored under kerosene. Reason (R): Metallic sodium melts when exposed to air. (a) Both A and R are true and R is the co

Science and TechnologyPractice
1996 • Q342Health & Medicine

Which one of the following elements is alloyed with iron to produce steel which can resist high temperatures and also have high hardness and abrasion

Science and TechnologyPractice
2024 • Q1Biotechnology & Genetics

"Membrane Bioreactors" are often discussed in the context of:

Science and TechnologyPractice
2024 • Q2Biotechnology & Genetics

Which one of the following is synthesised in the human body that dilates blood vessels and increases blood flow?

Science and TechnologyPractice
2024 • Q62Health & Medicine

Consider the following activities: 1. Identification of narcotics on passengers at airports or in aircraft 2. Monitoring of precipitation 3. Tracking

Science and TechnologyPractice
2024 • Q63Health & Medicine

Which one of the following words/phrases is most appropriately used to denote “an interoperable network of 3D virtual worlds that can be accessed simu

Science and TechnologyPractice
2024 • Q93Nanotechnology

In which of the following are hydrogels used? 1. Controlled drug delivery in patients 2. Mobile air-conditioning systems 3. Preparation of industrial

Science and TechnologyPractice
2024 • Q99Space & ISRO

Consider the following statements: Statement-I: Giant stars live much longer than dwarf stars. Statement-II: Compared to dwarf stars, giant stars have

Science and TechnologyPractice

Frequently Asked Questions — UPSC Prelims 1997 Q341

What is the official answer for UPSC Prelims 1997 GS Paper I Question 341 (Science and Technology)?

The official UPSC answer key for this 1997 Science and Technology (Health & Medicine) question is Option (A): "Fluorine". Correct attempts carry 2 Marks with -0.66 Negative penalty for wrong answers.

Which UPSC Prelims syllabus topic does this 1997 question belong to?

This question belongs to GS Paper I under the subject "Science and Technology" and micro-topic "Health & Medicine". You can explore all repeated questions from Health & Medicine in Acme AI's 3D Prelims PYQ Realm or practice 50 full-length and sectional tests in the APT Prelims Test Series.

How can I solve this Health & Medicine UPSC Prelims question using option elimination?

In Group 17 (halogens), chemical reactivity decreases down the group ($F2 > Cl2 > Br2 > I2$). Hence, Fluorine at the top is the most reactive.

Beyond Previous Year Questions

Structured Prelims Practice & Mentorship

Pair previous year question analysis with full-length simulated mock tests and 1-on-1 faculty guidance.

APT 2027 • 50 Prelims Tests17% OFF

Acme Prelims Test Series (APT)

Built to eliminate 1/3rd negative marking losses and 50–50 option traps through structured simulation and NCERT-backed keys.

  • 50 High-Yield Tests: Subject Sectionals, Current Affairs, CSAT Paper II & Full-Length Simulators
  • 1/3rd Penalty & Trap Analytics: Identify whether marks are lost to over-attempting or conceptual gaps
  • Option-by-Option NCERT Keys: Detailed distractor analysis and elimination logic for every question
  • Custom PDF-to-Mock Generator: Convert your revision notes or current affairs PDFs into practice tests
Complete 50-Test Package
₹1,493₹1,799• Valid till Prelims 2027
Explore APT Test SeriesTry Free Mock
1-on-1 Personal MentorshipCapped at 10 Seats

1-on-1 UPSC Mentorship with Avinash Sir

Weekly 1-on-1 strategy reviews, daily study accountability, and personalized MCQ attempt audits with an experienced UPSC mentor.

  • Weekly 1-on-1 Sessions: Direct mentorship with Avinash Sir (Former Plutus IAS Mentor, UPSC & UPPCS Mains Written)
  • APT 50-Test Series Included: Full Prelims GS1 & CSAT test series bundled at no additional cost
  • Mock Attempt & Elimination Audit: Question-by-question review to calibrate your risk and attempt accuracy
  • Prelims & Integrated Tracks: Available as dedicated Prelims mentorship or end-to-end Prelims + Mains guidance
Prelims & Integrated Tracks
17% OFF• Includes APT 50-Test Series
Explore 1-on-1 MentorshipCompare Tracks
Previous QuestionWhich one of the following pairs is correctly matched ?
Next QuestionMatch List I with List II and select the correct answer: | List–I (Functionaries) | List–II (Oaths or Affirmations) | | :--- | :--- | | A. President of India | 1. Secrecy of information | | B. Judges of Supreme Court | 2. Faithful Discharge of duties | | C. Members of Parliament | 3. Faith and Allegiance to the Constitution of India | | D. Minister for the Union | 4. Upholding the Constitution and the Law | Codes: