CAIE A Level Chemistry 9701 · Chemical bonding
Describe the intermolecular forces present in liquid ammonia () and liquid water (). In your answer, explain how bond polarity arises from electronegativity differences, and use your description to account for the relatively high melting point and surface tension of water, and the lower density of ice compared to liquid water.
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.
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