Abstract
The periodic table is a fundamental tool in understanding chemical behavior, yet it remains one of the most challenging topics for many Grades 8 students. School-based assessments have consistently identified it as a least mastered competency due to difficulties in understanding its organization and predictive use. These challenges highlight the need for instructional materials that make deep chemistry concepts more accessible and engaging. This study aimed to develop and validate a Strategic Intervention Material (SIM) titled "Follow the Order" to assist Grade 8 learners in mastering the periodic table. Anchored on competencies outlined in the Philippine K to 12 curriculum, the SIM used student-friendly activities, visual aids, and guided exercises to support learning. It underwent a rigorous validation process by subject matter experts to evaluate its content, format, presentation, accuracy, and up-to-datedness. Results showed that the SIM was rated Very Satisfactory across all domains, with mean scores ranging from 3.46 to 3.94 and low standard deviations, indicating strong agreement among evaluators. The material was conceptually accurate, free of grammatical and factual errors, and appropriate for junior high school learners’ cognitive levels. Illustrations and layout were found clear, relevant, and supportive of student engagement. Readability was assessed using the Flesch Reading Ease and Flesch-Kincaid Grade Level formulas, yielding scores of 60.2 and 5.6, confirming its suitability for students aged 13 to 15. Suggestions from validators were incorporated to improve the material’s quality and usability. While this study focused on development and validation, findings suggest SIM’s strong potential as a supplementary tool in Grade 8 Chemistry. Future research is recommended to evaluate its impact on student achievement, engagement, and retention in actual classroom settings.
