Free science experiments can be found in many of the science books, besides online. You just need to some good amount of research to get to the experiment that you are hunting for.
This is a boon for the teachers sometimes, as they can prepare a whole list of science experiments for the students to try in class. For the students it is again a blessing to get some free science experiments. For that extra learning and to be ahead of others you need to make a little effort and browse through the internet or get hold of some science books where you will find free science experiments.
Free science experiments give an opportunity to explore new things on your own. These free science experiments are basis real time events and have been conducted in the past by someone. Some of the free science experiments that you can hope to find on the internet are projects on battery power, simple magnet levitation experiments, generation of electricity through potato, lemon battery project, generation of electricity through bicycle, water electrolysis, solar system based projects, generation of electricity from fruits, vitamin c experiments, effect of detergent on plants, check of water level in oranges, water cycle creation, affect of vitamins on plants, and many more such experiments.
The list mentioned above is not exhaustive. Just ensure that your search is extensive enough and you are bound to get hold of many such science experiments of your interest. These experiments are detailed with instructions and materials required as well.
There are observations and results also described after the experiment detailing. Explanation of experiments is not limited, but expands to a lot more detailing. This gives you a complete knowledge of the subject and helps in quenching thirst for those knowledge seekers.