Which was a testable idea that J.J. Thomson developed through his experiments?
Atoms are the most important substances in the universe.
It is impossible to divide an atom into smaller parts.
There are electrically neutral particles inside atoms.
Atoms contain small, negatively charged particles.
Atoms are the most important substances in the universe.
It is impossible to divide an atom into smaller parts.
There are electrically neutral particles inside atoms.
Atoms contain small, negatively charged particles.