CIE iGCSE Co-Ordinated Science C9.3 Alloys and their properties Exam Style Questions Paper 1
▶️ Answer/Explanation
An alloy is a mixture of a metal with one or more other elements, which can be metals or non-metals. Examples include brass (copper and zinc) and stainless steel (iron with chromium and nickel). Alloys are not compounds because they do not have a fixed chemical formula and the elements are not chemically bonded. They are also not pure elements.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
Mixing a metal with another element to form an alloy disrupts the regular arrangement of atoms.
Atoms of different sizes prevent layers of atoms from sliding over each other easily.
This makes the alloy harder than the pure metal.
✅ Answer: (B)
Atoms of different sizes prevent layers of atoms from sliding over each other easily.
This makes the alloy harder than the pure metal.
✅ Answer: (B)
▶️ Answer/Explanation
Alloys are mixtures of metals, not chemically bonded compounds, since the elements are not combined in fixed proportions.
Because all alloys retain metallic bonding with delocalised electrons, all alloys conduct electricity.
✅ Answer: (C)
Because all alloys retain metallic bonding with delocalised electrons, all alloys conduct electricity.
✅ Answer: (C)
▶️ Answer/Explanation
Metals and alloys are giant structures of atoms, not molecules, so alloys are correctly described as being made up of atoms of each element.
In a pure metal, atoms are all the same size and can slide over one another easily, but alloying introduces atoms of a different size that disrupt this regular arrangement.
This disruption prevents layers of atoms from sliding smoothly, making the alloy harder than the pure metal.
✅ Answer: (A)
In a pure metal, atoms are all the same size and can slide over one another easily, but alloying introduces atoms of a different size that disrupt this regular arrangement.
This disruption prevents layers of atoms from sliding smoothly, making the alloy harder than the pure metal.
✅ Answer: (A)
Question
Metal X is extracted from its ore by heating the ore with carbon.
Which statement explains why carbon is used?
(A) Carbon is a non-metal.
(B) Carbon is more reactive than X.
(C) Carbon reacts with oxygen in the air.
(D) Carbon is less reactive than X.
▶️Answer/Explanation
Ans: B