iGCSE Chemistry 0620 Extended - 9.1 Properties of metals- Exam Style Questions Paper 2- New Syllabus
▶️ Answer/Explanation
A substance that reacts with dilute acids AND conducts electricity is most likely a metal (metals react with acids to give hydrogen gas and conduct electricity). Graphite is the only non-metal solid that conducts electricity, but it does not react with dilute acids. Ionic compounds in solid form do not conduct electricity (ions are locked in lattice). Student Y’s suggestion of a metal is the only fully consistent identification — metals satisfy both conditions: reacting with dilute acids and conducting electricity in the solid state.
✅ Answer: (C)
✅ Answer: (C)
▶️ Answer/Explanation
Brass is an alloy (a mixture) of copper and zinc, not a compound, so statement 2 is incorrect. Both pure metals and their alloys retain metallic bonding, so they conduct electricity – statement 1 is correct. Alloys are typically harder than their constituent pure metals because different-sized atoms distort the lattice and prevent layers from sliding, so statement 3 is correct. Hence, only statements 1 and 3 are correct.
✅ Answer: (C) 1 and 3 only
✅ Answer: (C) 1 and 3 only
▶️ Answer/Explanation
Let’s evaluate the options: Aluminium is renowned for its remarkably low density compared to transition metals like copper, making option A false. Aluminium is located significantly higher in the reactivity series than copper, making option B false. Copper is an outstanding electrical conductor used worldwide in wiring, ruling out option D. Option C is entirely correct because copper is highly ductile, meaning it can easily be pulled and stretched into thin conducting wires without snapping.
✅ Answer: (C)
✅ Answer: (C)