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Bromine is a liquid at room temperature and vaporises readily - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2022 - Paper 1
Question 5
Bromine is a liquid at room temperature and vaporises readily. Bromine has a simple molecular structure. Which row of the table shows the most likely melting and bo... show full transcript
Worked Solution & Example Answer:Bromine is a liquid at room temperature and vaporises readily - Edexcel - GCSE Chemistry Combined Science - Question 5 - 2022 - Paper 1
Step 1
Which row of the table shows the most likely melting and boiling points of bromine?
Answer
The melting point and boiling point of bromine must be consistent with its molecular structure, which suggests it exists as a liquid at room temperature. Thus, the most appropriate choice is Row B, which indicates a melting point of –17°C and a boiling point of 63°C. These values reflect the weak van der Waals forces present in simple molecular structures, allowing bromine to exist as a liquid at room temperature.
Step 2
Explain why graphene will be a good conductor of an electric current.
Answer
Graphene is an excellent conductor of electricity due to its unique structure. It consists of a two-dimensional lattice of carbon atoms arranged in a hexagonal pattern, which allows for the delocalization of electrons. This means that electrons can move freely across the surface, akin to how they move in metals. Furthermore, graphene has a high electron mobility, allowing it to conduct electricity efficiently. The presence of p-orbitals that overlap and form pi bonds contributes to the ability of graphene to exhibit high electrical conductivity, making it an ideal material for various electronic applications.