The Development of the Model of the Atom

Front

What was the initial belief about atoms before the discovery of the electron?

Back

Atoms were thought to be the smallest particle, a very small dense sphere that could not be split into pieces.

Front

What model was proposed after the discovery of the electron?

Back

The Plum Pudding Model, where electrons were thought to be buried inside a positive atom.

Front

What experiment did Rutherford conduct to investigate the atom further?

Back

Rutherford conducted the alpha particle scattering experiment, aiming an alpha particle beam at a gold sheet.

Front

What were the findings of Rutherford's alpha particle scattering experiment?

Back

Some particles went through the sheet, while others bounced back, indicating that the plum pudding model was incorrect.

Front

What model did Rutherford propose based on his experiment?

Back

The Nuclear Model, which suggested that the mass of the atom is concentrated at the center (nucleus), which is positively charged and small, with most of the atom being empty space.

Front

How did Niels Bohr change the nuclear model?

Back

Bohr proposed that electrons orbit the nucleus at specific distances linked to energy levels.

Front

What discovery did scientists make about the nucleus after Bohr's theory?

Back

The nucleus is made up of smaller particles called protons, each with a positive charge of +1.

Front

What was James Chadwick's contribution to the nuclear model?

Back

Chadwick discovered neutrons, uncharged particles with the same mass as protons, completing the nuclear model.

Front

What is the significance of neutrons in the atomic model?

Back

Neutrons account for the atomic and mass numbers, balancing the charges and masses in the atom.

Front

How do scientific models of the atom change over time?

Back

Scientific models are constantly adapted based on new experimental evidence, as seen with the transition from the plum pudding model to the nuclear model.