Question

exam 1: atomic theory/structure
which idea of daltons is no longer considered part of the modern view of atoms?
in a chemical reaction, atoms are not created, destroyed or changed, only rearranged
atoms of different elements can combine in different ratios to form different compounds
atoms of the same element are all identical.
matter is made up of atoms which are extremely small particles.

Explanation:

Isotopes show atoms of same element can vary in neutrons. So, "Atoms of the same element are all identical" is outdated.

Answer:

Atoms of the same element are all identical.