7th grade science fair task ideas are likely more involved than the projects you've done in former years. The science fair at your school is likely more competitive for your age group and there's a good occasion your peers will be putting a lot more time and effort into their projects than they have in former years, so you'll want to do the same for your 7th grade science projects.
One fascinating idea might be to see which type of cheese mold will grow on the fastest. This is a great task because it's interesting, but still fairly simple. Other idea for a task might be to see if you can grow a plant without soil. You can try placing seeds in various things such as a wet paper towel, grass clippings, coffee grounds, etc to see if they will grow. Be creative!
You could find out whether the proximity of smoke in the air affects plant transpiration. Perhaps you could look into whether or not there is ever acid snow, we all know there is acid rain, but what about snow? You can find this out by testing the Ph level of the snow and comparing it to the Ph level of acid rain. Obviously this singular task only works in the winter months. There are many great topics out there for your 9th grade science project, it's just a matter of seeing one that interests you, researching and testing it out and presenting it in a pro manner.
