A student rubs a steel nail across a bar of white soap and then across a glass tile. The nail leaves a deep groove in the soap but no mark on the glass. What does this test show?

Two blocks are both painted bright red, but one can be scratched with a fingernail and the other cannot. What is the best conclusion?

A class needs a material for the back of a bicycle safety reflector. Which measured property matters most for this job?

A student tests four samples with a battery and a small bulb. The bulb lights only when the copper strip is in the circuit. What does the copper's behavior show?

A metal spoon and a wooden spoon stand in the same mug of hot water. After two minutes the metal spoon handle feels hot and the wooden handle still feels cool. What property is being compared?

An unknown gray sample is shiny and very hard, but a magnet does not pull on it at all. A student says it must be iron. Why is that claim not supported?

A harder material can leave a scratch on a softer material.

A student stirs a spoonful of white powder into warm water and it disappears from sight, leaving a clear liquid. Which property has been tested?

Three samples are tested. Sample 1 is shiny and pulled by a magnet. Sample 2 is shiny and ignored by the magnet. Sample 3 is dull and ignored by the magnet. Which sample could be an iron nail?

An engineer must pick a material for a pot handle so the handle stays cool while the pot heats on a stove. Which property should the material have?

Two students test the hardness of four rock samples. One student presses hard with the scratching tool and the other presses lightly. What must they change to make this a fair test?

A designer needs a surface for a bathroom mirror. She shines a flashlight on four materials and compares how bright a spot each one makes on the wall. Which property is she measuring?

A tool is needed to cut grooves into hard tile. Which measured property should the cutting edge have?

Two clear samples look exactly alike. One dissolves completely in water and the other does not dissolve at all. What is the best claim this evidence supports?

A student sorts materials by whether a magnet pulls on them. Aluminum foil and a copper wire are not attracted, but a paper clip is. What does this show about the paper clip?

A mystery strip looks just like the copper wire from an earlier test, shiny and reddish. But when a student clips it into the same battery-and-bulb circuit, the bulb stays dark. What is the best conclusion?

A team needs a lunch box lid that stays cool in a warm car. They rest a metal lid and a thick plastic lid on the same warm surface for five minutes. The metal lid feels hot; the plastic lid still feels cool. Which material suits the job, and why?

A polished silver tray and a sheet of black felt sit in the same sunny window. The tray sends a bright patch of light onto the ceiling and the felt sends none. What does this compare?

A worker needs a covering for an electric wire so that a person holding the wire does not get a shock. Which property should the covering material have?

Three minerals are tested. Quartz scratches feldspar, and feldspar scratches calcite. Which mineral is the hardest of the three?