CIE iGCSE Co-Ordinated Science C9.3 Alloys and their properties Exam Style Questions Paper 2
▶️ Answer/Explanation
An alloy is a mixture of a metal with other elements, where atoms of different sizes disrupt the regular metallic lattice. Diagram A (with different sized atoms) correctly represents this. The others show pure metal or other structures.
✅ Answer: (A)
✅ Answer: (A)
▶️ Answer/Explanation
Brass is an alloy, which is a mixture of two or more metals. Specifically, brass is a mixture of copper and zinc. It is not a compound because the copper and zinc atoms are not chemically bonded together in a fixed ratio; they are physically mixed. Option A is incorrect because brass contains the elements copper and zinc, not compounds of them. Option B is incorrect because brass is not a compound. Option C is incorrect because brass is a mixture of the two metals, not a metal and a compound.
✅ Answer: (D)
✅ Answer: (D)
▶️ Answer/Explanation
Alloys are mixtures, not compounds, since the metals are simply combined together without any fixed chemical formula or new chemical bonds forming between them.
Since all alloys are made of metals (with metallic bonding retained), all alloys still conduct electricity, just like the pure metals they are made from.
So gap 1 should be “mixtures” and gap 2 should be “All”.
✅ Answer: (C)
Since all alloys are made of metals (with metallic bonding retained), all alloys still conduct electricity, just like the pure metals they are made from.
So gap 1 should be “mixtures” and gap 2 should be “All”.
✅ Answer: (C)
▶️ Answer/Explanation
Alloys are made of atoms (not molecules) of different elements mixed together, since metals consist of atoms held by metallic bonding.
The different-sized atoms disrupt the regular layers of a pure metal lattice, preventing layers sliding easily, so alloys are harder than the pure metals.
✅ Answer: (A)
The different-sized atoms disrupt the regular layers of a pure metal lattice, preventing layers sliding easily, so alloys are harder than the pure metals.
✅ Answer: (A)
Question
When iron is galvanized, it is coated with a layer of zinc.
Which statements about galvanizing are correct?
1 Zinc has a greater tendency to form positive ions than iron.
2 Zinc prevents iron from rusting by sacrificial protection.
3 Iron is more reactive than zinc.
4 Zinc acts as a barrier method of rust prevention if scratched.
(A) 1 and 2
(B 1 and 4
(C) 2 and 3
(D) 3 and 4
▶️Answer/Explanation
Ans : A