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This question is about metals and alloys - AQA - GCSE Chemistry - Question 3 - 2015 - Paper 2
Question 3
This question is about metals and alloys. 3 (a) Explain how electricity is conducted in a metal. To gain full marks you must include a description of the structure ... show full transcript
Worked Solution & Example Answer:This question is about metals and alloys - AQA - GCSE Chemistry - Question 3 - 2015 - Paper 2
Step 1
Explain how electricity is conducted in a metal.
Answer
Electricity is conducted in metals due to the presence of a giant structure of atoms, arranged in a lattice or close-packed layers. The metal comprises positive ions surrounded by a sea of delocalized electrons. These delocalized electrons are not bound to any particular atom, enabling them to move freely throughout the metallic structure. As a result, when a potential difference is applied, these electrons can flow and carry a charge, allowing for electrical conductivity.
Step 2
Describe how the structure of an alloy is different from the structure of a pure metal.
Answer
An alloy, which is a combination of two or more elements, typically has a structure that consists of different types or sizes of atoms. In contrast, a pure metal has a regular arrangement of identical atoms. The presence of varied atoms in an alloy creates distorted layers, which disrupts the orderly arrangement found in pure metals and contributes to altered properties.
Step 3
Why is Nitinol used in dental braces?
Answer
Nitinol is utilized in dental braces due to its properties as a 'smart alloy' or memory alloy. This means it can return to its original shape after being deformed, making it effective for orthodontic applications where gradual realignment of teeth is required.
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Step 7
Give two reasons why instrumental methods of analysis are used to detect impurities in metals.
Answer
Instrumental methods of analysis are preferred for detecting impurities in metals because they are accurate and sensitive. Additionally, these methods require only a small sample size, making them efficient for testing.