What is an interesting and unique science project idea for a fifth grader?

Answer 1

try a density experiment. an ordinary egg will sink to the bottom of a cup of water. but saline or salt water is more dense and an egg will float. put the egg in a bowl of warm, but not hot water (it sinks) add some salt and watch as the egg rises to the top. whether an object sinks of floats depensds on its density. one cupful of water, for example, is lighter than one cupful of egg, so the density of the egg is greater than the density of water. this means the egg will sink in water. when you add salt, the water becomes more dense than normal water and more dense than the egg. this means the egg will rise to the surface. curious fact, 97% of all water on the earth is salt water and of the 3% fresh water, only about 1/10th is in our rivers, streams and lakes. the rest is in glaciers.