CAIE A Level Chemistry 9701 · Atoms, molecules and stoichiometry
A student writes the following definition in a notebook.
'The relative atomic mass of an element is the mass of one atom of its most abundant isotope divided by one twelfth of the mass of a carbon-12 atom. The relative molecular mass of a substance is measured in grams.'
Explain why both parts of this statement are wrong.
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.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.