A few good middle school experiments can include mold growth, egg bungee jump, saltwater conductivity, DNA extraction from a vegetable, making magnets and a potential energy project, as noted by the Education website. Some other interesting science experiments or projects for these grade levels, which are available at the Science Projects Resource website, are plant germination, the factors affecting the evaporation of water, crystal formation and a fruit battery.
Most students in middle school do experiments in different science classes, such as life science, biology and chemistry. Some other common experiments or projects for these classes can be mold growth, crystal formation and the effects of different substances on plant growth.
There are many experiments that students can do on plants, such as the effects of salt or sugar water, light, soil's pH level, vinegar or oil on their growth. Many science experiments for these grade levels can also involve how sugar or salt crystals form. For this experiment, simple materials are necessary, including string, water, sugar or salt, jar and a pencil. The experiment shows how the solute (either sugar or salt) precipitates out of the cooled solution as it evaporates over time to form a solid or crystal formation on the string. Another aspect of this experiment that students can also study is how does temperature affect crystallization.
There are many more experiments that middle grade school children can do, and they are available at the Science Project Resources and Education websites.