The internet can be used to your advantage and you are sure to be able to find the perfect 7th grade science project for your student that will fulfill their science fair requirements, and hopefully follow their interests as well. The trick is to know where to look to get the best and most results.
Start by searching more generally for science projects that suit your 7th grader’s science interests. For example, if they want to do a science experiment that has to do with star gazing or space, you can search “7th grade science projects, astronomy” to be sure to find a project that is appropriate for their grade level. Odds are, however, that you will need to find a more specific science project website in order to get the best results.
There are certain websites that exist that host whole databases of science projects for kids of all ages, and can be searched by grade level or subject area. Some great science project databases include http://www.akronlibrary.org/DBS/SFDB/Default.aspx as well as http://www.youth.net/nsrc/sci/sci.index.html. These websites that are intended specifically for students searching for feasible and fun science projects will likely be more reliable and easy to use than doing a broader search, where the results might be hard to verify. Another good resource are the 7th grade project guides available for free at http://www.middle-school-science-projects.com/guide.pdf, that are designed with the usual hypothesis through results structure in mind.