A student is given four solid samples labeled W, X, Y, and z. All except Z have a metallic luster. She is told that the solids are gold, lead sulfide, quartz (SiO2), and iodine. The results of her investigation are: w is a good electrical conductor while X, Y, Zare poor electrical conductors
When hit with a hammer w flattens out, x shatters into many pieces, Y is smashed into powder and Z is cracked
When heated with a Bunsen burner, Y melts with some sublimation, but X, W, and Z do not melt
When treated with concentrated acid, X dissolves but there is no effect on W, Y, and Z
On the basis of the test results, identify the solids.