Learners explore how recyclers take advantage of the different properties of materials, such as magnetism and density, to separate them from a mixture. They use a magnet and floatation to separate screws, plastic, and aluminum from a mixture of pre-made "trash." The screws are removed from the mixture by a magnet, flotation separates out "trash" like yogurt cups and other plastics, and aluminum and other non-magnetic and non-floating bits of "trash" are left. This activity is part of the Environmental Chemistry unit in OMSI's Chemistry Lab. Material estimates are for 100 uses.