Some good ideas for a ninth-grade science project are an experiment to determine the effectiveness of teeth whiteners, ways to keep bread fresh longer, and what makes a clothes dryer more efficient. They do not require a large amount of time, and all references used to research project topics should be cited.
For the teeth whitener project, several test members can be enlisted to experiment with one brand of teeth whitener, or several brands, and progress measured depending on the hypothesis. Finding ways to make a clothes dryer more efficient involve trying different variables to determine which actions make clothes dry faster.
A suitable science project for a ninth-grader involves determining ways to affect the germination rate of seeds. Seeds can be pre-rinsed in a fruit juice or in chemicals such as diluted hydrochloric acid solution, diluted isopropyl alcohol solution or hydrogen peroxide. The experiment can be to check if the chemicals loosen the coating around the plant embryo and how it changes the seed germination.
Projects to deduce if listening to music helps memory, what type of material creates the best sound for speakers, what affects a light bulb life span, and measuring the amount of acid in rain are also suitable ninth-grade science experiments.