Fifth graders are well suited to science lessons focused on learning the scientific method, the basics of changes in matter and organisms. Lesson-specific information is available from Time 4 Learning, Education.com and HotChalk Lesson Plans.
According to Time 4 Learning, fifth graders can begin their study of science by exploring the process of scientific investigation. This involves identifying problems that can be solved through experimentation, making a plan for the experience and actually conducting at least one experiment while collecting and organizing the data and analyzing the findings. By starting with this exploration, the fifth grader is in a good position to practice his understanding of this methodology on future projects.
Some fun experiments to conduct with fifth grade students include making slime, making a Cartesian Diver and discovering why leaves change color. Other experiments include making marbleized paper, using flowers to make tests for acids and bases and learning to make ice cream in a plastic bag. These can be tied into lessons focused on both changes in matter and organisms. Details on these experiments can be found on Education.com.
HotChalk also provides lesson plans focused on understanding Doppler radar and habitat studies, as well as learning about the water cycle.