1997 General Studies, all questions

UPSC Prelims 1997 · General Studies

Question 113: Science and Technology

The most reactive among the halogens is

afluorine
bchlorine
cbromine
diodine

AnswerThe answer is (a).

Among the halogens, reactivity falls going down the group: fluorine, chlorine, bromine, iodine. Fluorine is the most electronegative element and combines with almost everything, even with some noble gases such as xenon. It is the smallest halogen, and its weak F-F bond is easy to break.

Why each option is right or wrong
  • (a) Right: fluorine is the most reactive halogen.
  • (b) Chlorine is less reactive than fluorine.
  • (c) Bromine is less reactive than chlorine.
  • (d) Iodine is the least reactive of the four.

Explanation: written by UPSC Grade, not by UPSC.

Practise this paper timedPrevious questionNext question

Source: UPSC, Civil Services (Preliminary) Examination 1997, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.