Answer:Answer: The step that is NOT necessary to complete before a cuvette is placed into the spectrophotometer is option B (Write, in ink, either sample or blank on the side of the cuvette to keep track of them)
Explanation: spectrophotometer is an instrument used to measure the light intensity absorbed after being passed through a solution. Before the absorbance of the sample solution, a solvent solution called blank is used for the calibration of the machine and this blank solvent is placed in a cuvette. The procedure usually comes first before the main sample is processed. Therefore there is no need to
Write, in ink, either sample or blank on the side of the cuvette to keep track of them. This is so since sample and blank is not absorbed at the same time by the machine.
They move like waves since they're such a small particle
Answer: Region 3
Explanation: The temperature and time graph suggests that region 3 is the region in which the substance can co exist in both the phases that is solid phase and liquid phase.
Region 1 explains that the the solid has just started melting and there occurs a break point and then region 2 again explains that the solid is taking more time with temperature to get converted into the liquid and thus region 3 explains the equilibrium between the two phases.
Chromatography A process use mixed liquid