Final answer:
When Marie and Calvin dissolve 50 grams of KBr in 100 grams of water at 90°C, the resulting solution is a homogeneous mixture called a liquid solution.
Step-by-step explanation:
When Marie and Calvin dissolve 50 grams of KBr in 100 grams of water at 90°C, the resulting solution is a homogeneous mixture called a liquid solution. In this case, KBr, which stands for potassium bromide, is the solute, and water is the solvent. The solute particles, in this case, KBr, are dispersed uniformly throughout the water, resulting in a clear and transparent solution.