Eighth-grade science fairs are an opportunity for students to get really in-depth with an area of scientific inquiry they find personally fascinating. Choosing the right topic can be a challenge, as the entire project depends on whether the topic is viable for research and will create interesting results. When picking a topic, consider what you personally find inspiring about science and build an idea from there.

Biology, which is the study of life and living organisms, can be a fascinating area of scientific inquiry for eighth graders. Some eighth-grade appropriate biology science fair topics include, "How much light do plants need to survive?" "What conditions are ideal for growing mold?" "Where is the richest soil found?" "What effect do fertilizers have on dying plants?" and "Do some plants produce more oxygen than others?"

Chemistry is the study of matter and the changes it goes through. Chemistry is a good area of science for eighth graders interested in experimenting with making matter change through chemical processes. Some topic ideas for science fair projects could be "How quickly can you dissolve salt in water?" "How do you make water change from a gas to a solid?" "Can sea water be desalinated?" and "Which chemicals put out fire the most effectively?"

Physical science encompasses physics and and the physical world. Physical science projects are good for eighth-grade students interested in machines and how they work. Some project ideas could include "How do pulleys make lifting a weight easier?" "What compound machine is best suited to different tasks?" "Which surface is the best for pushing a weight on?" "What type of metal is the best for conducting heat?" and "Can paint help prevent rust?"

Behavioral science is the interesting world of studying why people act the way they do. Behavioral science projects are particularly well suited for eighth graders, as they can use their peers as test subjects. Some possible behavioral science project ideas are "How does music affect memory?" "What affects people's reflexes?" "How much can we trust memory?" "What is the ideal environment for learning?" and "Can people differentiate between different brands of food by taste?"