Atomic Models in Physics

Democritus proposed that matter is made up of indivisible particles called '______'.

J.J. Thomson developed the '______ pudding model' of the atom.

J.J. Thomson's work led to the discovery of the '______'.

Ernest Rutherford discovered the '______' through his gold foil experiment.

The Nuclear Model of the Atom indicates that the atom is mostly '______'.

The Bohr Model describes electrons orbiting the nucleus in specific '______'.

James Chadwick discovered the '______', a subatomic particle with no electric charge.

The modern quantum mechanical model of the atom was developed by '______'.

Early Atomic Models

Democritus proposed the "atomos," indivisible particles, as the fundamental building blocks of matter.
J.J. Thomson's plum pudding model depicted the atom as a sphere of positive charge with negatively charged electrons embedded within.
Thomson's cathode ray tube experiment discovered the electron as a negatively charged particle.

Rutherford's Nuclear Model

Rutherford's gold foil experiment revealed a small, dense, positively charged nucleus at the atom's center.
The nuclear model illustrates that most of the atom is empty space, with the nucleus containing nearly all the mass.
The nucleus is positively charged, while electrons orbit the nucleus at significant distances.

Bohr Model

The Bohr model postulates that electrons orbit the nucleus in specific energy levels.
Electrons in this model do not continuously emit radiation; instead, energy is exchanged in discrete jumps between energy levels.

Chadwick's Neutron

James Chadwick discovered the neutron in 1932.
Neutrons are electrically neutral and have a mass similar to protons.

Quantum Mechanical Model

The quantum mechanical model, developed by Schrödinger, Heisenberg, and Born, describes electrons as wave-like particles.
This model predicts the probability of finding an electron in a specific region around the nucleus, instead of fixed orbits.

Test your knowledge on the early atomic models proposed by Democritus, Thomson, Rutherford, Bohr, and Chadwick. This quiz covers fundamental concepts such as the structure of the atom and the discovery of subatomic particles.