alleryWhy do some metals look dull instead of shiny after a long time?
AThey become softer with time
BThey absorb too much sunlight
CAir and moisture act on them
DThey turn into wood slowly
Answer & Solution
Correct answer: C. Air and moisture act on them
1. Metals are normally lustrous.
2. Air and moisture act on some metals and make them look dull.
3. That is why lustre is often seen only on freshly cut surfaces.
_Source: NCERT Curiosity Class 6 Science, Ch 6, 6.3.1_
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