Why is john dalton known as the originator of atomic theory? a. he was the first to propose that matter is made of atoms. b. he proved that atoms are divisible in nature. c. he based his theory on philosophical assumptions. d. he could scientifically explain the theory of atoms.

Option A: He was first to propose that matter is made of atoms.

John Dalton proposed that matter is made up of indivisible atoms. Here atoms are like building blocks of matter and can not be further destroyed. For an element, all atoms are identical but for different elements, they can vary in mass and size. Also, in compound, atoms of elements always combine in fixed ratio by mass.

Option B is incorrect because according to him atom is indivisible as subatomic particles were not discovered at that time.

Option C and D are also incorrect as he does not made any philosophical assumptions and also he could not scientifically explain his theory of atoms.