2025 AQA GCSE Biology Paper 2 Complete Practice Exam

In chromatography, the correct answer identifies the two phases as the stationary phase and the mobile phase. The stationary phase is the substance that remains fixed in place, while the mobile phase is the solvent that carries the mixture to be separated. This separation is based on different affinities for both phases, allowing various components of a mixture to travel at different rates, resulting in a separation of substances.

This distinction is key because the efficiency of the chromatography process relies on how well the components of a mixture interact with both the stationary and mobile phases. The nature of these phases can greatly affect the outcome of the separation. Understanding these phases is crucial for successfully interpreting chromatographic results and applying this technique in various scientific fields.