CAIE A Level Chemistry 9701 · States of matter

States of matter: describe question

Describe7 marksChallenge

Describe, in simple terms, the lattice structure of each of the following crystalline solids.

(a) magnesium oxide, $\ce{MgO}$ (b) ice, $\ce{H2O}$ (c) graphite, $\ce{C}$

For each substance, explain how its structure and bonding account for one of its physical properties:

for (a) its high melting point (2852 °C)
for (b) its melting point (0 °C)
for (c) its ability to conduct electricity.

How this question is marked

7 marks, so the mark scheme is looking for about 7 separate creditworthy points. Making the same point twice in different words earns it once.

Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.

States of matter: describe question

How this question is marked

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