CAIE A Level Chemistry 9701 · The Periodic Table: chemical periodicity
The oxides of the elements in Period 3 (, , , , , ) show a trend in their reactions with water and their acid-base behaviour.
Compare the behaviour of these oxides when added to water. Include equations for any reactions that occur, state the approximate pH of the solutions formed, and explain the trend across the period in terms of bonding and electronegativity.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.