The many theories, formulas, and elements that must be memorized make chemistry subjects considered complicated especially if it is not accompanied by the selection of an appropriate learning model, it certainly affects the student learning outcomes. This study aims to determine the effect of the Learning Cycle 7E learning model on buffer material on the learning outcomes of Class XI students of SMA N 2 Langowan by using independent variables (Learning Cycle 7E) and dependent variables (learning outcomes). The research sample is students of Class XI MIPA 1 and XI MIPA 2 in SMA N 2 Langowan, the sample is determined by the Simple Random Sampling technique. The research method used is Quasi Experiment Design with Posttest-only Control Group Design research design. Testing of research instruments (post test) consists of validity and reliability tests. Data analysis method uses homogeneity test, normality test and t-test. Based on the analysis of the data it was found that the sample was homogeneous and normally distributed, t-test data at the real level (α) = 0.05 was obtained tcount = 9,489 and ttable = 2,042. Because tcount> ttable, reject H0 and H1 are accepted. Based on the results of the study concluded that there was an influence of the Learning Cycle 7E learning model on the buffer solution material on the learning outcomes of Class XI students of SMA N 2 Langowan with an average learning outcome in the experimental class 80.00 and the control class 35.59.

Tujuan dari studi ini untuk mengetahui informasi pengaruh model pembelajaran Problem Based Learning (PBL) pada hasil belajar Hukum-Hukum Dasar Kimia dan besar Effect Size. Penelitian ini dilakasanakan di SMA Negeri 1 Buko dengan menggunakan metode Experimental Design yakni Nonequivalent Control Group Design. Populasi dalam penelitian adalah seluruh siswa kelas X IPA SMA Negeri 1 Buko. Sampel terdiri dari dua kelas yang dipilih  menggunakan teknik Random intact class dengan masing-masing berjumlah 25 orang. Teknik pengumpulan data menggunakan pretest dan posttest. Hasil pengujian hipotesis uji t dengan taraf signifikan  = 0,05 diperoleh nilai thitung = 24,8 lebih besar dari ttabel = 2,010. Oleh karena itu maka H0 ditolak dan H1 diterima. Penelitian ini disimpulkan terdapat peningkatan hasil belajar antara kelas PBL dan kelas Konvensional dengan Effect Size sebesar 92,79%.

The impact of the use of refined petroleum on potential pollution in mangrove allows the presence of lead metal (Pb) in the Sangihe Islands Restoration and Learning Center and the use of mangroves in the Sangihe Islands Restoration and Mangrove Learning Center as a place of learning has not been carried out to the full. Therefore, in this regard, a study was carried out by analyzing Pb metals in sediments, Gastropod shells and Bivalvia shells in the research subsystem zone of the Sangihe Islands Restoration and Mangrove Learning Center which were then designed into learning designs using a model of problem based learning. The research method used is an exploratory method. Pb metal analysis was performed using an Atomic Absorption Spectrophotometer instrument resulting in an average Pb metal in sediments was 0.402 ppm, in Bivalvia shells was 0.04283 ppm and Gastropods shells was 0.0654 ppm. Based on the results of the analysis, it can be concluded that the presence of Pb metal in sediments, Bivalvia shells and Gastropod shells then yields four main questions in the learning design with Sub-Impacts of the Use of Petroleum using the problem based learning model.

Penelitian ini bertujuan untuk mengetahui kelayakan produk LKS praktikum berbasis pendekatan saintifik dan mengetahui dampaknya pada hasil belajar khususnya  materi sifat larutan penyangga dengan melihat seberapa banyak siswa yang mencapai  atau melampaui KKM. Jenis penelitian ini adalah penelitian dan pengembangan yang dilakukan di kelas XI IPA 5 SMAN 1 Tondano. Berdasarkan hasil rekapitulasi, LKS praktikum berbasis pendekatan saintifik dinyatakan valid dengan nilai sebesar 83,8%. Dilihat dari respon siswa pada uji coba kelompok kecil dan kelompok besar LKS dinyatakan praktis dengan nilai berturut-turut sebesar 88,17% dan 92,98%. Dampak penggunaan LKS terhadap hasil belajar siswa adalah sebagian besar siswa pada uji coba kelompok kecil dan siswa pada uji coba kelompok besar telah melampaui KKM yang sudah ditetapkan dengan nilai ketuntasan yang diperoleh berturut-turut sebesar 66,67% dan 89,47%. Pengujian hipotesis untuk hasil belajar menggunakan uji t pihak kiri diperoleh nilai thitung(8,517) > ttabel(1,734) yang berarti terima H0 atau tolak H1. Berdasarkan hasil yang diperoleh dapat disimpulkan bahwa LKS praktikum berbasis pendekatan saintifik yang dikembangkan layak digunakan dalam proses pembelajaran.