17) bend dissolve react tarnish melt combust evaporate
The underlined words indicate chemical changes: the substance has changed into something with a different composition.
The other words represent physical changes: the substance changes its form but not its composition.
19) rust burn decompose boil tarnish dissolve break bake cut
The underlined words indicate physical changes. The other words represent chemical changes
18) solid < liquid < gas
The particles of a solid are fixed in place. Those in a liquid can slide past each other. Gas particles can move around the vulome of their container,
