The student clearly stated the independent variable as the pH of the soaking solution and the dependent variable as the iron concentration in spinach. The research question included a thorough description of the analysis method, specifically the use of a spectrophotometer, and the background theory effectively connected pH levels to iron concentration. However, the student did not provide a clear explanation of the techniques used to measure iron concentration; this would be improved by detailing the calibration and measurement processes. The student successfully discussed controlled variables, safety,y, and environmental concerns, and outlined a reproducible methodology without irrelevant information. Ethical considerations were not adequately addressed, as the student failed to explain the absence of ethical issues during the investigation.
