The The Effect of Guided Inquiry Learning Model on Improving Students’ Learning Outcomes in the Periodic Table of Elements Material in Class X at SMA Negeri 1 Sidikalang

This research was conducted at SMA Negeri 1 Sidikalang in the 2024/2025 academic year, involving two classes as research subjects. The experimental group, namely Class X MIPA 5, was given learning using a guided inquiry model, while the control group, namely Class X MIPA 6, was given learning using the traditional method. Each class consists of 36 students. The purpose of this study was to determine the effectiveness of the guided inquiry learning model in improving students' understanding of the material on the periodic table of elements. This study used a pretest-posttest design with non-equivalent groups. Data analysis was carried out quantitatively. The results of the t-test showed that the average increase in student learning outcomes in the experimental class reached 79.0%, while in the control class it was 69.6%. Hypothesis testing using the t-test with degrees of freedom (df) 35 and a significance level of α = 0.05 showed that the calculated t value (th = 23.46) was greater than the t table (tt = 2.03). This indicates that there is a significant difference between the two groups. Thus, the null hypothesis (H₀) is rejected and the alternative hypothesis (Hₐ) is accepted. Based on the results of the analysis, it can be concluded that the guided inquiry learning model is effective in improving student learning outcomes on the material of the periodic table of elements.