Lead and aluminum look very similar, especially in pellet form. A common science project --- separating a mixture of pellets of these two materials --- makes use of their physical properties. A magnet would attract neither metal, but a simple way to separate them can teach you about density at the same time.

    1. Pour all the pellets into a bucket or other large container. Ensure that the pellets do not fill the container more than halfway so that there is space above them.
    2. Fill the container the rest of the way with water so that there is about as much water in the container as there is metal.
    3. Watch for the aluminum pellets to float to the surface. They float because aluminum is less dense --- that is, lighter --- than water. Lead is heavier and denser than water, so it sinks.
    4. Scoop out the aluminum pellets with the fishnet, sieve or just your hands. You have now efficiently separated the two types of metal.