Science (086) — AI-generated practice question

Suspension 1 (very fine particles): The scattered light appears blue. Fine particles preferentially scatter shorter wavelengths (blue light), similar to how air molecules scatter blue light to make the sky appear blue.

Suspension 2 (larger particles): The scattered light appears white (or a mixture of longer wavelengths). Larger particles scatter light of longer wavelengths as well, and if the particles are large enough, all visible wavelengths are scattered, making the scattered light appear white.

Reason: The colour of scattered light depends on the size of the scattering particles. Very fine particles scatter mainly blue light (shorter wavelengths), while larger particles scatter light of longer wavelengths too, eventually appearing white.

Source: Chapter 10, Section 10.6.1 – Tyndall Effect

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• The key textbook line is: "Very fine particles scatter mainly blue light while particles of larger size scatter light of longer wavelengths. If the size of the scattering particles is large enough, then, the scattered light may even appear white."
• Examiners expect you to clearly name the colour for each suspension and give the reason linked to particle size vs. wavelength.
• Don't just say "blue light is scattered more" — connect it to particle size being the deciding factor.