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6. (a) Explain, in terms of their structure, how metals conduct electricity - Edexcel - GCSE Chemistry - Question 6 - 2017 - Paper 1
Question 6
6. (a) Explain, in terms of their structure, how metals conduct electricity. (b) Oxygen is a simple molecular, covalent substance. The electronic configuration of a... show full transcript
Worked Solution & Example Answer:6. (a) Explain, in terms of their structure, how metals conduct electricity - Edexcel - GCSE Chemistry - Question 6 - 2017 - Paper 1
Step 1
Explain, in terms of their structure, how metals conduct electricity.
Answer
Metals conduct electricity due to the presence of delocalised electrons. These electrons are not bound to any specific atom and can move freely throughout the metal lattice. This movement allows electric charge to flow when a potential difference is applied, enabling metals to conduct electric current efficiently.
Step 2
Draw the dot and cross diagram of an oxygen molecule, O2. Show outer electrons only.
Answer
The dot and cross diagram for an oxygen molecule (O2) illustrates two oxygen atoms sharing two electrons, creating a double bond. Each oxygen atom has 6 outer electrons, represented as follows:
O: •• •• :O
: • :
The dots represent the electrons from one atom, while the crosses represent the electrons from the other.
Step 3
Explain why potassium chloride has such a high melting point.
Answer
Potassium chloride (KCl) has a high melting point due to the strong electrostatic forces of attraction between the oppositely charged ions (K+ and Cl-). A large amount of energy is required to overcome these ionic bonds, resulting in a high melting temperature.
Step 4
Explain, using ideas about their structures, why diamond and graphite are suitable for these uses.
Answer
Diamond and graphite have distinct structural properties that lend to their unique uses:
Diamond: It has a tetrahedral structure where each carbon atom is covalently bonded to four other carbon atoms, forming a rigid and strong lattice. This makes diamond extremely hard, making it suitable for cutting tools.
Graphite: In contrast, graphite has a layered structure where carbon atoms are arranged in sheets that can slide over each other. This structure allows graphite to act as a lubricant and a good conductor of electricity in electrodes, as the delocalised electrons can move freely within the layers.