Question

Atoms are indivisible but how one can tell that atoms having protons electrons..

Answer 1

They were thought to be indivisible; scientists have since realised that this is wrong. As far as the 18th to 19th century chemists knew, the atom was the smallest unit of matter, and that idea worked for a long time. Then J.J Thompson discovered a tiny particle called the electron and left the scientific community a little puzzled; people had to figure out how “the smallest unit of matter” could contain a particle 2000 times smaller!

Answer 2

all knows that atoms very are small which we can't see with our eyes therefore we can say that it contain electron and proton by seeing an atom with microscope