Question

Which is a component of John Dalton’s atomic theory?
The ratio of atoms in a compound can vary.
The atoms of a single element differ.
An atom is a small particle that cannot be broken down.
Atoms of different elements can be identical.

Answer 1

"An atom is a small particle that cannot be broken down."

Dalton's atomic theory proposed that atoms are indivisible, indivisible particles; the other statements contradict Dalton (he said atoms of a given element are identical, atoms of different elements differ, and compounds have fixed whole‑number ratios).