Question

Which of the following statements is NOT a part of John Dalton's atomic theory?

a. Every compound is composed of atoms of different elements, combined in a specific ratio.
b. Electrons move in specific orbits around the nucleus of an atom.
c. All atoms of the same element are exactly alike and have the same mass.
d. All elements are composed of atoms that cannot be divided.

Answer 1

@Kainui @freckles

Answer 2

@shadow13

Answer 3

clue: the masses of an element vary depending on the amount of proton and neutrons present

further discussion:
Dalton did not know that atoms can be further broken down. The technology of his time were not capable of breaking an atom down.