A good science project researches what scientists already know about that topic. 

example:

MAIN IDEA

DETAILS

What nutrients does a bean plant need to grow? Nitrogen, carbon, hydrogen, oxygen, phosphorous, potassium, sulfur, calcium, iron, and magnesium
What does a bean plant need nitrogen for? Nitrogen is used to make plant proteins. These plant proteins are then used to make the protoplasm in a plant cell. These nitrogen based proteins are also stored as food in the plant’s cells. Nitrogen is also needed to make chlorophyll, amino acids, alkaloids, and some plant hormones. As such, the rate growth of a plant is greatly influenced by the amount of nitrogen available.

WB01584_.gif (2068 bytes)