General Knowledge - General Science

Exercise : General Science - Elements and Metals
21.
When an iron nail gets rusted, iron oxide is formed
without any change in the weight of the nail
with decrease in the weight of the nail
with increase in the weight of the nail
without any change in colour or weight of the nail
Answer: Option
Explanation:
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22.
Galvanised iron sheets have a coating of
lead
chromium
zinc
tin
Answer: Option
Explanation:
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23.
Among the various allotropes of carbon,
coke is the hardest, graphite is the softest
diamond is the hardest, coke is the softest
diamond is the hardest, graphite is the softest
diamond is the hardest, lamp black is the softest
Answer: Option
Explanation:
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24.
The group of metals Fe, Co, Ni may best called as
transition metals
main group metals
alkali metals
rare metals
Answer: Option
Explanation:
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25.
Heavy water is
deuterium oxide
PH7
rain water
tritium oxide
Answer: Option
Explanation:
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