a corn is a kind of object & popping popcorn requires adding heat to the corns & adding heat to an object sometimes causes chemical reactions ->  popping popcorn will cause chemical reactions to the corns  popping popcorn will cause chemical reactions to the corns & chemical reactions cause different substances to form ->  popping popcorn will cause a different substance to form  popping popcorn will cause a different substance to form & different substances have different chemical properties -> popping popcorn will cause a different substance with different chemical properties to form