Pretest Answers

Which mixture can be separated based on differences in the particle size of the components?

During which method of separation is one of the components of the mixture lost?

Carlotta adds too much salt to her soup. She recalls that evaporation can be used to separate salt from salt water, so she plans to leave the soup on the stove on low heat until the soup is less salty. Which will most likely happen to her soup?

Which method of separating a mixture involves passing a heterogeneous mixture through several layers of different materials?

Which method is best for separating most of a solid from a gas quickly?

Julie’s town uses single-stream recycling, so Julie puts all of her household recyclables in a single container to be picked up. The recycling plant must sort out the different materials, including paper, cardboard, different types of plastic, glass bottles and jars, aluminum drink cans, and steel food cans. How would an electromagnet be used in this type of recycling plant?

Different periods in human history are named for the materials used to make tools. Dr. Franklin is searching through layers of soil, looking for tools made by humans. After screening the top layer of soil, he uses a magnet to help speed up the search. Which type of location is Dr. Franklin most likely searching?

What property allows salt to be collected from ocean water?

Maria works in a hardware store. A bin of aluminum nails and a bin of iron nails are knocked over, and the nails get mixed up. Both sets of nails are the same color and size. What makes separating the nails a fairly easy job?