This study is based on the generative learning model which involves context-based learning. Using the generative learning model, we taught the topic of Halogens. This topic is covered in the grade 10 chemistry curriculum using activities which are designed in accordance with the generative learning model supported by context-based learning. The purpose of this study was to ascertain the effects of the activities on students' motivation towards context-based chemistry learning, their attitudes towards chemistry lessons and their level of success in understanding the halogen concepts that were taught. The sample of the study consisted of 60 grade 10 students in a high school in Ankara, Turkey. The study was conducted using a pretest-posttest design with a control group of 30 students and a treatment group of 30 students. The Context-Based Chemistry Motivation Scale, the Attitudes towards Chemistry Scale and the Halogens Achievement Test were used as data collection tools in the study. The study concluded that the context-based learning activities improved students' motivation in learning chemistry and their attitudes towards the chemistry course as well as increasing their achievement levels in the test.