CIE iGCSE Co-Ordinated Science C9.1 Properties of metals Exam Style Questions Paper 2
▶️ Answer/Explanation
Good electrical conductivity is a universal property of all metals due to the presence of delocalised electrons in their metallic structure. Option A is incorrect because metals are malleable and do not break when hit (they dent or bend). Option C is incorrect because most metals do not dissolve in water (though some react). Option D is incorrect because not all metals have high densities (e.g. lithium and sodium have low densities). Therefore, only option B applies to all metals.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
Hydrogen comes from \(CH_4 + H_2O \rightarrow CO + 3H_2\) (methane reacted with steam).
Nitrogen is obtained separately by fractional distillation of liquefied air, since air is about \(78\%\) nitrogen.
✅ Answer: (D)
Nitrogen is obtained separately by fractional distillation of liquefied air, since air is about \(78\%\) nitrogen.
✅ Answer: (D)
▶️ Answer/Explanation
Metals are generally malleable and good thermal conductors, so rows A and B correctly link property to element type.
Non-metals typically have low melting points compared to metals, so row D is also a correct link.
Non-metals are generally poor electrical conductors, not good ones (except graphite), so row C incorrectly links electrical conductor to non-metal.
✅ Answer: (C)
Non-metals typically have low melting points compared to metals, so row D is also a correct link.
Non-metals are generally poor electrical conductors, not good ones (except graphite), so row C incorrectly links electrical conductor to non-metal.
✅ Answer: (C)
▶️ Answer/Explanation
A more reactive metal can displace and reduce the oxide of a less reactive metal.
Magnesium is more reactive than copper, so it can remove oxygen from copper oxide, reducing it to copper metal.
Calcium and sodium are both more reactive than magnesium, and magnesium oxide is already the oxide of magnesium itself, so these cannot be reduced by magnesium.
✅ Answer: (B)
Magnesium is more reactive than copper, so it can remove oxygen from copper oxide, reducing it to copper metal.
Calcium and sodium are both more reactive than magnesium, and magnesium oxide is already the oxide of magnesium itself, so these cannot be reduced by magnesium.
✅ Answer: (B)
▶️ Answer/Explanation
Zinc is more reactive than iron, not the other way round, so statement 1 is incorrect.
Because zinc is more reactive, it oxidises in preference to iron, protecting the iron underneath — this is sacrificial protection, so statements 2 and 4 are correct.
As long as any zinc coating remains nearby, it continues to protect the iron even if scratched, so statement 3 is incorrect.
✅ Answer: (C)
Because zinc is more reactive, it oxidises in preference to iron, protecting the iron underneath — this is sacrificial protection, so statements 2 and 4 are correct.
As long as any zinc coating remains nearby, it continues to protect the iron even if scratched, so statement 3 is incorrect.
✅ Answer: (C)