Question

Over time, scientists have changed the atomic model as new information has become available. Give an example of evidence from the video that led to a change in the model of the atom.

Answer 1

Marie Curie studied radioactive substances for many years. In 1902, she introduced a theory that a few kinds of atoms can disintegrate and eject energetic particles. She was convinced that atoms aren’t made of one particle. In this way, Dalton’s atomic model changed.

In 1904, Joseph John Thomson discovered electrons while he was studying cathode rays. He concluded that a stable atom has negatively charged particles and an equal number of positively charged particles. These characteristics make an atom neutral in charge.

Answer 2

The model of the atom that is missing from the set is the Thomson’s model. J. J. Thomson portrayed his atom model to look like a plum pudding. In his model, he described that an atom is composed mainly of electrons.