chem demo

Democritus

First proposed the idea of the atom and theorized that matter cannot be divided forever; smallest piece = atomos (‘not to be cut’).

Atomos

The smallest piece of matter that cannot be divided, as proposed by Democritus.

Billiard Ball Model

John Dalton's model of the atom, depicting it as solid, uniform spheres.

Plum Pudding Model

J.J. Thomson's model of the atom, consisting of a positively charged sphere with electrons scattered inside.

Gold Foil Experiment

An experiment by Ernest Rutherford that discovered the nucleus and concluded that atoms are mostly empty space.

Nuclear Model

Rutherford's model proposing that electrons orbit a small, dense, positively charged nucleus.

Bohr Model

Niels Bohr's model suggesting that electrons orbit the nucleus in fixed energy levels.

Spectroscope

A device developed by Kirchhoff and Bunsen to study the specific line spectra emitted by energized elements.

Matter Waves

Proposed by Louis de Broglie, this concept states that particles like electrons exhibit both particle and wave properties.

Uncertainty Principle

Proposed by Werner Heisenberg, stating that one cannot know both the position and energy of an electron simultaneously.

Quantum Mechanical Model

Developed by Erwin Schrödinger, this model describes electrons as existing in 3D orbitals based on probability.

Who first proposed the idea of the atom?

Democritus

What did Democritus theorize about matter?

That it cannot be divided forever; its smallest piece is 'atomos'.

Atomos

The smallest piece of matter that cannot be divided, as proposed by Democritus.

What does 'atomos' mean?

'Not to be cut' or indivisible.

Which scientist proposed the Billiard Ball Model?

John Dalton

How did the Billiard Ball Model depict atoms?

As solid, uniform spheres.

Who proposed the Plum Pudding Model?

J.J. Thomson

Describe J.J. Thomson's Plum Pudding Model.

It consists of a positively charged sphere with electrons scattered inside, like plums in a pudding.

Who conducted the Gold Foil Experiment?

Ernest Rutherford

What was discovered as a result of the Gold Foil Experiment?

The atomic nucleus.

What key conclusion about atomic structure came from the Gold Foil Experiment?

Atoms are mostly empty space.

Which scientist developed the Nuclear Model?

Ernest Rutherford

What did Rutherford's Nuclear Model propose about electrons?

They orbit a small, dense, positively charged nucleus.

Who developed the Bohr Model?

Niels Bohr

What was a key feature of the Bohr Model regarding electron orbits?

Electrons orbit the nucleus in fixed energy levels.

Who developed the spectroscope?

Kirchhoff and Bunsen

What is the purpose of a spectroscope?

To study the specific line spectra emitted by energized elements.

Who proposed the concept of Matter Waves?

Louis de Broglie

What does the concept of Matter Waves state?

Particles like electrons exhibit both particle and wave properties.

Who proposed the Uncertainty Principle?

Werner Heisenberg

What does Heisenberg's Uncertainty Principle state?

One cannot know both the position and energy of an electron simultaneously.

Who developed the Quantum Mechanical Model?

Erwin Schrödinger

How does the Quantum Mechanical Model describe electrons?

As existing in 3D orbitals based on probability.