The student includes an Objective and Aims section, where they clearly identify the main focus of the study. However, the research question is not well-formed as it does not specify the pH values of the solutions used, and the dependent variable mentioned in the question is not the same as the actual variable being tested. The student provides relevant and focused background information, highlighting the conditions and factors contributing to teeth discoloration. However, the biology explanation could be improved by making clearer connections with biological processes, such as linking teeth to the digestive system. The student does not state the hypothesis correctly, as they need to first state the null hypothesis and then the alternative hypothesis. The methodology of the investigation is not appropriate to the topic and does not focus on answering the research question, as the choice of the dependent variable is inconsistent. However, the student does demonstrate awareness of safety, ethical, and environmental concerns that can arise during the experiment.
