A student has 2 samples of steel wool. One with very fine strands and the other with thick strands but both have the same mass. Observation: put a lit match under the fine wool and set fire itself. Put a match under the thick wool and would not burn. What is the model for this observation?

Question

jfraser · Answer

the sample of steel woll with thin strands has the same mass, and so the same # of Fe atoms as the thick strand. The difference in the thickness means that there are more thin wires, and so more surface area. This is a problem of RATE, or the speed at which a reaction occurs.

anonymous · Answer

Combustion occurs at the surface of the steel.  Since the finer-stranded steel wool has a larger surface area, it supports a greater amount of combustion.