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