Some fourth grade science activities and projects include self-inflating balloons, corn seed germination and sundials. A child can also do something more environmentally focused by mapping classroom or home energy use or creating an ocean food web.
A child can show how balloons can be inflated either with baking soda or biogas derived from garbage, the latter of which can be used as a form of energy. Biogas-inflated balloons show how the natural decomposition of waste releases methane and carbon dioxide that can be useful forms of energy. The child needs to blend together different combinations of fruits and vegetables and pour each blend into empty plastic bottles. After labeling the bottles with the fruits and vegetables used in the puree, the child stretches the mouth of a balloon over the mouth of the plastic bottle and duct tapes it in place. Then, he simply waits for the purees to decompose and release gas.
Another good project explores the relationship between different forms of life found in the ocean. The student needs to decorate a piece of cardboard to make it resemble an ocean. Then, he must begin adding living organisms to the cardboard, starting with plants and other producers like phytoplankton. The student draws or pins a picture of the animal to the board and labels it, moving from phytopankton to zookplankton, herring, salmon, seals and killer whales. He can stretch a piece of yarn from one organism to the organism it feeds on it to live.