Assessment and Qualifications Alliance (AQA) GCSE Biology Paper 2 Practice Exam

When different ions are mixed together and subjected to flame tests, the phenomenon that occurs is that some flame colours can be masked. This means that the presence of certain ions can overshadow or diminish the visibility of the flame colour that would normally be produced by another ion.

For instance, if sodium ions are present, they produce a strong yellow flame that can mask the colours produced by other metal ions, like potassium, which typically produces a lilac flame. This masking effect occurs because the bright yellow flame of sodium is more intense and can overpower the lighter colours, making them difficult to observe.

Understanding this concept is crucial when interpreting results from flame tests, as it emphasizes the need to consider which ions are present and how their interactions might affect visibility. The masking of colours can lead to misinterpretation of the flame tests if the dominant colour is not taken into account.