%I UNIVERSITAS SULTAN AGENG TIRTAYASA %X 21st century skills such as critical thinking are essential to help students face global challenges. However, the results of the 2018 PISA study showed that Indonesian students' scientific reasoning skills are still low. Therefore, an effective learning strategy is needed, one of which is through chemistry learning. Chemistry, as part of science, helps train critical thinking skills through analysis and problem solving based on scientific data. Hydrocarbon combustion material that is relevant to environmental and health issues is considered appropriate to be integrated with the Problem Based Learning (PBL) model based on Socio-Scientific Issues (SSI). This study aims to determine the difference in students' critical thinking skills before and after the SSI-based PBL model is applied to hydrocarbon combustion material. This type of research is quantitative pre-experimental with a pretest-posttest one group design. The research was conducted in the even semester of 2024/2025 with a sample of 30 students selected through a purposive sampling technique. The instruments used were Teaching Modules, LKPD, KBK Observation Sheets and KBK test questions. The data were analyzed descriptively using Microsoft Excel and inferentially using SPSS version 27. The results showed an increase in students' critical thinking skills after implementation, with an average score increase of 37%. Hypothesis testing showed a sig. (2-tailed) <0.001, which means there is a significant difference. In addition, the results of the non-test of KBK achievement were 89% with a very good category. Thus, the SSI-based PBL model is effective in improving students' critical thinking skills. %L eprintuntirta51204 %T PENERAPAN MODEL PROBLEM BASED LEARNING BERBASIS SOCIO-SCIENTIFIC ISSUES UNTUK MENINGKATKAN KEMAMPUAN BERPIKIR KRITIS SISWA DALAM SISTEM MOVING CLASS PADA MATERI PEMBAKARAN HIDROKARBON %A VAKHA AL AMIN %O Keterampilan abad ke-21 seperti berpikir kritis sangat penting untuk membantu siswa menghadapi tantangan global. Namun, hasil studi PISA 2018 menunjukkan kemampuan bernalar ilmiah siswa Indonesia masih rendah. Oleh karena itu, dibutuhkan strategi pembelajaran yang efektif, salah satunya melalui pembelajaran kimia. Kimia, sebagai bagian sains membantu melatih kemampuan berpikir kritis melalui analisis dan pemecahan masalah berbasis data ilmiah. Materi pembakaran hidrokarbon yang relevan dengan isu lingkungan dan kesehatan dinilai tepat untuk diintegrasikan dengan model Problem Based Learning (PBL) berbasis Socio-Scientific Issues (SSI). Penelitian ini bertujuan untuk mengetahui perbedaan kemampuan berpikir kritis siswa sebelum dan sesudah diterapkan model PBL berbasis SSI pada materi pembakaran hidrokarbon. Jenis penelitian ini adalah kuantitatif pre-experimental dengan pretest-posttest one group design. Penelitian dilaksanakan pada semester genap tahun2024/2025 dengan sampel 30 siswa yang dipilih melalui teknik purposive sampling. Instrumen yang digunakan yaitu Modul Ajar, LKPD, Lembar Observasi KBK dan soal tes KBK. Data dianalisis secara deskriptif menggunakan Microsoft Excel dan secara inferensial menggunakan SPSS versi 27. Hasil penelitian menunjukkan adanya peningkatan kemampuan berpikir kritis siswa setelah penerapan, dengan rata-rata peningkatan skor sebesar 37%. Uji hipotesis yang menunjukkan nilai sig. (2-tailed) < 0,001, yang berarti terdapat perbedaan signifikan. Selain itu, hasil non-tes ketercapaian KBK sebesar 89% dengan kategori sangat baik. Dengan demikian, model PBL berbasis SSI efektif meningkatkan kemampuan berpikir kritis siswa. %D 2025