Physical v. Chemical Properties & Changes

anything you can observe or measure about a material

density, melting point, boiling point, & freezing point can all be MEASURED without changing the substance into a new substance

chemical properties indicate they will change the substance into something else

if something is flammable, it can catch on fire and when it burns, it will turn into a new substance

the identity of the substance stays the same

example: ice is water in a solid form. when it melts, it's still water, just in the liquid form. melting is a physical change!

you ARE NOT changing what the substance is, just what it looks like!

change one substance into something else

example: iron on the outside of a car will react with oxygen in the air to create rust, which is a new substance

basically: what you have before HAS TO equal what you have after a reaction

if 5 substances have a mass of 150g before a reaction that creates 1 substance, that 1 substance will have a mass of 150g