How has the understanding of the arrangement of electrons in an atom changed since the late 1800's?

Answer 1

The electron was discovered by J.J. Thomson in 1897, when he discovered particles inside the atom that contains a negative electric charge. Since then, scientists have learned much more about electrons, and the way they are imagined has changed as well. Niels Bohr established that there was a structure to the way electrons are laid out within the atom, and this discovery has changed the study of physics.