The Evolution of Atomic Theory Flash Cards

Front

Place the following atomic models in chronological order: Quantum Mechanical Model, Bohr Model, Dalton's Solid Sphere Model, Rutherford's Nuclear Model, Thomson's Plum Pudding Model.

Back

1. Dalton's Solid Sphere Model, 2. Thomson's Plum Pudding Model, 3. Rutherford's Nuclear Model, 4. Bohr Model, 5. Quantum Mechanical Model

Front

Why have atomic models been replaced over time?

Back

New experimental evidence led to the development of more accurate models.

Front

Thomson's Plum Pudding Model (1897) Main features:

Back

Electrons are embedded in a positively charged sphere

Front

Rutherford's Nuclear Model (1911) Main features:

Back

The atom has a small, dense nucleus at its center.

Front

Why was Rutherford's Nuclear Model (1911) replaced?

Back

It could not explain the stability of atoms.

Front

Bohr's Model (1913) is characterized by which of the following main features?

Back

Electrons revolve in fixed orbits around the nucleus

Front

Modern Quantum Mechanical Model (1920s) Main features:

Back

Electrons exist in probability clouds called orbitals

Front

The three main subatomic particles in an atom are:

Back

Proton (positive, nucleus), Neutron (neutral, nucleus), Electron (negative, electron cloud)

Front

What determines which element an atom is?

Back

The number of protons in the atom

Front

An isotope is:

Back

Atoms of the same element with different numbers of neutrons