Hi, What do you think is the answer to this question? That would be your hypothesis to test with an experiment.

Here is more on the scientific method and how to develop a science project:
http://www.education.com/reference/article/Ref_What_Scientific/
http://www.education.com/reference/article/Ref_How_Develop_Project/

Here are two similar science projects:

Use Water to Produce Energy
http://www.education.com/reference/article/Ref_Use_Water_Produce/

Water Electrolysis
http://www.education.com/reference/article/Ref_Water_Electrolysis/

Please also refer to any materials or information your teacher provided, and ask your parent for help with your project as needed as well. Good luck!

Yes definitely.

Make Electricity from Saltwater and Oxygen
Introduction:

Chemical energy stored in different substances can be converted to electrical energy. This ability is the foundation of design of all batteries.  

Each battery has two poles usually made of two different metals. One pole is the positive pole and the other is the negative pole. Electrons can travel from negative pole to the positive pole via a conductor such as a wire.
 
 A flow of electrons in a conductor is called electricity and if large enough, it can be used to make electro magnet, light up a light bulb or run an electric motor. Inside each battery there are chemicals that cause such chemical reactions. These chemicals in general are called electrolytes.
 
 Project description:
In this project you will make a salt water battery and then perform a series of experiments to determine how does the amount of oxygen affect the life and the power of the battery.
 Details of this project:
More details or support on this project is available for the members of ScienceProject.com. Material needed for experiment or a science kit about this title may be available at MiniScience.com and klk.com online stores.

Yes and I am also do Salt Water Energy for my Science Fair Project.

no,because salt and water really dosen't make anything,but salt water.

salt is made of chlorine and sodium ions.when you put salt in water, the water molecules pull the sodium and chlorine ions apart and  so they float freely.these ions carry electricity through water

maybe. but it can turn on litghs.