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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 o... 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 are free to move throughout the metal lattice. When a voltage is applied, these delocalised electrons flow through the metal, allowing the conduction of electric current.
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 O2 molecule consists of two oxygen atoms. Each oxygen atom contributes six outer electrons, and they share a pair of electrons. The diagram shows two dots representing the shared electrons, indicating a double bond between the two oxygen atoms.
O:O
In this representation, one oxygen is represented with dots and the other with crosses to illustrate the sharing.
Step 3
Explain why potassium chloride has such a high melting point.
Answer
Potassium chloride has a high melting point due to the strong electrostatic forces of attraction between the oppositely charged ions (K+ and Cl-). These forces create a strong ionic bond, requiring a large amount of heat energy to break the bonds when melting.
Step 4
Explain, using ideas about their structures, why diamond and graphite are suitable for these uses.
Answer
Diamond is structured in a three-dimensional lattice where each carbon atom is covalently bonded to four other carbon atoms. This strong bonding gives diamond a high hardness, making it suitable for cutting tools.
In contrast, graphite consists of layers of hexagonally arranged carbon atoms. Within each layer, the atoms are bonded strongly, but the layers are held together by weak van der Waals forces. This allows the layers to slide over each other easily, which makes graphite an excellent lubricant and suitable for use in electrodes.