“Luster” means, basically, how shiny it is. Most metals are shiny and nonmetals are not. “Malleability” refers to how easily something can be molded or beaten into a different shape. Although not all metals are soft enough to change shape without heat, they are still considered malleable. Nonmetals are not malleable because are too brittle; they break and crumble instead. “Conductivity” means the ability to conduct heat and electricity. Metals are conductive and nonmetals aren’t. Additional properties of metals are that they are dense (heavy) and they react to acid.
Collect some samples of easily obtainable metals, nonmetals and metalloids, such as iron filings, sulfur, graphite (replacement leads for mechanical pencils), charcoal (carbon), silicon or objects like paper clips, metal BBs -- air gun pellets -- copper wire or nails. You will also need a solution of hydrochloric acid, a hammer, and a conductivity apparatus – something with an open electrical circuit and a light bulb, for example. If working with older children, split them into groups and give each group their own samples, bottle of solution with eye dropper and hammer, and pass the conductivity apparatus around.
All students will need a chart that allows them to mark or describe the characteristics of each sample they look at. The point will be for them to determine which samples have the characteristics of metals, which have the characteristics of nonmetals and which have a mixture of the two. Make a chart of your own or download one from the Internet (see Resources).
Have all the students look at the samples to notice their color and luster. Older children can conduct the next steps themselves in groups, while younger children should watch as an adult does them before the class. To test malleability, try to crush the substance with a hammer. If it breaks into pieces then it is not malleable. Put a small amount in a test tube and drop the acid on it to see if it reacts. Finally, test the sample for conductivity using the apparatus. If the bulb lights up when you close the circuit using the sample, you know that it’s conductive.