CAIE A Level Chemistry 9701 · Atomic structure
Magnesium has three naturally occurring isotopes: , , and . Their relative abundances are 78.99%, 10.00%, and 11.01% respectively.
Describe what is meant by the term isotope, and explain why these three isotopes of magnesium have the same chemical properties but different physical properties, such as density.
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.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.