Metallic bonding and types of crystal structureAQA A-Level Chemistry: Flashcards

What these 12 flashcards ask

What is metallic bonding?
Why does Mg have a higher melting point than Na?
Why can metals be hammered into shape?
Why does NaCl conduct when molten but not when solid?
Why is diamond very hard?
Why does graphite conduct?
Why is graphite soft and slippery?
Why does graphite still have a very high melting point?
What is broken when iodine melts?
What type of structure is ice?
Why is the temperature constant during melting?
Why does boiling need more energy than melting?

Exam questions on Metallic bonding and types of crystal structure

A technician is testing four unlabelled solids at room temperature. Solid W conducts electricity, is malleable and melts at 650 °C. Solid X does not conduct as a solid, conducts when molten and melts at 801 °C. Solid Y does not conduct in any state and melts at 114 °C. Solid Z is very hard, does not conduct and melts above 3500 °C.
Explain why solid X conducts electricity when molten but not when solid.2 marks
A student compares sodium, which melts at 98 °C, with magnesium, which melts at 650 °C. Both metals conduct electricity as solids and both can be hammered into shape.
Explain why sodium can be hammered into shape without breaking.2 marks
Graphite and diamond are both forms of carbon. Graphite is used as electrodes and as the 'lead' in pencils, which leave a mark because layers rub off onto paper. Diamond is used on the cutting edges of drill bits.
Explain why graphite conducts electricity but diamond does not.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).