<p>Elementary science education often does not reflect the processes used n professional science. Students are instructed in a recipe-oriented way to follow predetermine procedures in order to come to predetermined results. The embedding of critical thinking skills instruction into science curriculum makes it possible for science instruction to more closely resemble professional science. This curriculum development thesis utilizes critical thinking skills and instructional strategies as a basis for embedding critical thinking skills instruction into a series of lessons on the topic of sound. Each lesson includes objectives for science content and thinking skills, a motivational activity, use of portfolios for metacognition, and an activity to promote the transfer of the targeted thinking skills. Students work in cooperative learning groups to which they belong during the entire lesson series. A trial implementation of the lessons was conducted in a suburban, heterogeneous, self-contained, third grade classroom. It became clear that this method of teaching requires more student and teacher input and greater effort than traditional methods. The role of the teacher shifts from director to facilitator, and the students become much more involved in the direction their learning takes. Based on constant observation, the teacher must design activities and ask questions which motivate students to continually reshape and modify their thinking. Students demonstrated an improved ability to accept science as a work in progress, developed questioning skills, and learned to transfer knowledge to new situations. They also began to recognize discrepancies between past and present thinking. Yet some students held on to misconceptions and showed resistance to change in light of opposing evidence. One example of these misconceptions is the belief that sound always passes through transparent objects. This thesis not only provides sample lessons for other teachers, but also serves as a stepping stone for further investigation of students' misconceptions about sound.</p>