It is quite usual for you to give your clothes for dry washing. But have you ever wondered why people opt for dry washing when they can easily clean the clothes at home. So if you can do a project to establish whether dry cleaning is better than the usual wet cleaning or not, it will be definitely something out of the ordinary. At the same time it will capture the attention of your judges and the audience as it is something they do in their everyday life but know very little about it. The elementary science fair projects will help you understand how chemicals are used to clean coffee and fruit stains from different fabrics.
Bread is something that is a part of our daily breakfast. If you can do a project on how temperature affects the mold growth on bread it will be equally interesting. This project will help your audience to understand how they can prevent molding in food. Bread manufactures have to keep these things on mind to prevent mold growth from bread.
The hypothesis here is that mold growth is slower in a freezing temperature than at a warm temperature. Low temperature prevents several enzymatic reactions that play an integral role in spoiling the food. Through your experiments you can show how storing food inside a freezer is more effective than storing the same thing in the refrigerator. You can show the variations in mold growth at different temperatures.