The educational possibilities of combining four powerful teaching strategies (context-based teaching, inquiry-based teaching, murals, and augmented reality) in the learning of the chemical elements are reported in this paper. We present a project involving 15-year-old students who research and identify the chemical elements present in food using an inquiry-based approach. Students organize their findings in four categories according to the role of the chemical element in the food (major elements, essential trace elements, toxic trace elements, and chemical food preservation). Conclusions were disseminated through a large mural with audio QR codes where results can be explored for students using a smart phone. To investigate the effectiveness of the project we ask students to identify chemical elements in food and whether their intake was beneficial or harmful to health, before (pretest) and after (post-test) the project. In the first case, only five foods (milk products, bananas, lentils, water, and salt) made up 100% of responses in pretest and 80% in post-test. In the second case, the chi-square test showed significant differences between pretest and post-test, with students mentioning both beneficial and harmful effects on health to a greater degree after the project. However, no significant differences were detected in pretest and post-test justifications, even though a wider variety of responses were found in the post-test in all cases. Finally, a concept inventory for elements in food is proposed from the students’ responses.

中文翻译：

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发现食物中的化学元素

本文报道了在化学元素的学习中结合四种强大的教学策略（基于上下文的教学，基于探究的教学，壁画和增强现实）的教育可能性。我们提出了一个由15岁的学生组成的项目，他们使用基于查询的方法来研究和识别食品中存在的化学元素。学生根据食物中化学元素的作用（主要元素，必需微量元素，有毒微量元素和食品化学防腐剂）将研究结果分为四类。通过带有音频QR码的大型壁画散发结论，可以使用智能手机为学生探索结果。为了调查该项目的有效性，我们要求学生在项目进行前（测试前）和测试后（测试后）识别食物中的化学元素，以及摄入的食物是否对健康有益或有害。在第一种情况下，只有五种食物（奶制品，香蕉，小扁豆，水和盐）在前测中占100％，在后测中占80％。在第二种情况下，卡方检验显示出测试前和测试后的显着差异，项目结束后，学生在更大程度上提到了对健康的有利和有害影响。但是，尽管在所有情况下的测试后发现了各种各样的回答，但在测试前和测试后的证明中均未发现显着差异。最后，根据学生的回答提出食物中元素的概念清单。