What concept in dalton’s atomic theory has been modified? a. all matter is composed of atoms. b. atoms of different elements have different properties and masses. c. atoms can combine in chemical reactions. d. atoms cannot be divided.

(D) Atoms cannot be divided

Explanation: It wasn't until around 2,000 years later, in the early 1800s, when John Dalton came along and disproved Aristotle. Dalton went on to say that matter is made up of tiny particles, called atoms, that cannot be divided into smaller pieces and cannot be destroyed.

c is the answer because when something is left after something evaporates that shows the chemical change.