Is "sharpening a pencil" more of a physical change than souring of milk, fermenting of grape juice or rusting of iron?
Chemistry - DrBob222, Saturday, July 24, 2010 at 8:31pm
definitely. Sharpening a pencil leaves the lead, the wood, and the eraser in their original formulations. The others you mention changes the composition of the milk, grape juice or iron into something else.
Chemistry - Kris, Saturday, July 24, 2010 at 9:36pm
Thanks, Dr. Bob. So are new substances formed in a chemical reaction?
Chemistry - DrBob222, Saturday, July 24, 2010 at 10:14pm