CAIE A Level Chemistry 9701 · Atomic structure
Hydrogen has three isotopes: hydrogen-1, hydrogen-2 and hydrogen-3. The symbols and represent hydrogen-2 and hydrogen-3. Compare these two isotopes in terms of the numbers of protons and neutrons in each nucleus, the meaning of the numbers 2 and 3 in their symbols, their chemical properties and their physical properties.
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.