![ A light beam from a laser pointer passes through three beakers. Beaker 1: The beam is invisible inside the liquid. Beaker 2: The beam is visible as a glowing line through the liquid. Beaker 3: The liquid is opaque and cloudy, and the beam is blocked or scattered randomly. ]

Based on the diagram and the observation of light scattering, which beaker contains a colloid?

In a fractional distillation setup, what is the primary purpose of the glass beads or packing inside the fractionating column?

On a completed chromatogram, the term 'solvent front' refers to the:

In paper chromatography, the paper itself acts as the __________ phase.

In the process of municipal water treatment, allowing heavy dirt and silt particles to sink to the bottom of a large tank is an application of __________ to separate a mixture.