Metallic bonding and giant structuresEdexcel A-Level Chemistry: Flashcards

What these 13 flashcards ask

Define metallic bonding.
Why do metals conduct electricity?
Why are metals malleable?
Why does solid sodium chloride not conduct, but molten sodium chloride does?
What type of structure is silicon(IV) oxide, and how are its atoms bonded?
Why is diamond very hard?
Why does graphite conduct electricity?
Why is graphite soft and a good lubricant?
What is graphene?
What is broken when iodine melts?
Why is ice less dense than liquid water?
Why is iodine insoluble in water?
A solid has a high melting temperature and conducts when solid. What structure is it likely to have?

Exam questions on Metallic bonding and giant structures

An electrician is comparing copper wire with a lump of solid sodium chloride as materials for use in a circuit. Copper has a melting temperature of 1085 °C and sodium chloride melts at 801 °C.
Explain why copper conducts electricity but solid sodium chloride does not.2 marks
Graphene is a single layer of carbon atoms arranged in a flat hexagonal pattern. Researchers are investigating it as a conductor for flexible touch screens.
Explain why graphene conducts electricity whereas diamond does not.2 marks
A technician is given four solids, W, X, Y and Z, and records their properties. W melts at 801 °C, dissolves in water, and conducts electricity only when molten or in solution. X is yellow, melts at 115 °C, does not dissolve in water and does not conduct electricity in any state. Y melts at 1085 °C, does not dissolve in water and conducts electricity when solid. Z melts at 1710 °C, is very hard, does not dissolve in water and does not conduct electricity in any state; it contains only silicon and oxygen. X is known to be made of S₈ molecules.
Deduce the type of structure and bonding in W, in Y and in Z, giving one piece of evidence from the data for each.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).