Three students discuss the origin of the distinct pink color of Lake Hillier, a hypersaline lake.
* Student 1 proposes that the pink color is caused by pigments produced by halophilic microalgae and bacteria.
* Student 2 proposes that the pink color is due to dissolved iron- and cobalt-rich minerals leaching from the lake bed.
* Student 3 proposes that the pink color is a physical optical effect of light scattering off suspended microscopic salt crystals.
Match each student's hypothesis with the experimental outcome that would directly invalidate it.
- Student 1's hypothesis (pigments from halophilic microorganisms)Lake water is passed through a micro-filter to remove all cells, but the filtrate remains pink.
- Student 2's hypothesis (dissolved iron- and cobalt-rich minerals)Spectroscopic analysis of the pink lake water shows zero concentration of dissolved transition metals.
- Student 3's hypothesis (light scattering by suspended salt crystals)The pink water is heated to dissolve all suspended micro-crystals, but the color does not change.
Cevap
Student 1's hypothesis matches with the micro-filter cell removal outcome; Student 2's hypothesis matches with the spectroscopic metal analysis outcome; Student 3's hypothesis matches with the crystal dissolution by heating outcome.
Each hypothesis is paired with the experimental action that isolates and removes its proposed cause (cells, metal ions, or crystals) to see if the pink color persists. If the color persists after the cause is eliminated (or if the cause is shown to be absent), that hypothesis is invalidated.
Adım Adım Çözüm
Anahtar Kavram
Suggesting Experiments to Resolve Viewpoints