2008 General Studies, all questions
UPSC Prelims 2008 · General Studies
Question 116: Science and Technology
Which one of the following pairs of metals constitutes the lightest metal and the heaviest metal, respectively?
aLithium and mercury
bLithium and osmium
cAluminium and osmium
dAluminium and mercury
AnswerThe answer is (b).
Lithium is the lightest metal, with a density of about 0.53 g per cubic centimetre, light enough to float on water. Osmium is the densest element known, at about 22.6 g per cubic centimetre, so it is the heaviest metal by density. Aluminium is light but denser than lithium, and mercury is dense for a liquid but far lighter than osmium.
Why each option is right or wrong
- (a) Lithium is the lightest, but mercury at about 13.5 g per cubic centimetre is not the densest.
- (b) Lithium is the lightest and osmium the heaviest.
- (c) Aluminium is denser than lithium, so it is not the lightest.
- (d) Aluminium is not the lightest and mercury is not the heaviest.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2008, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.