Atomic Models in Chemistry

Flashcards covering different atomic models in chemistry, highlighting their key characteristics and evidence.

Dalton’s Atomic Model (1803)

Proposed that matter is composed of indivisible and indestructible atoms, with identical atoms for each element and compounds formed in fixed ratios.

Thomson’s Atomic Model (1897)

Also known as the 'Plum Pudding Model', it depicts the atom as a positively charged sphere with negatively charged electrons embedded within it.

Rutherford’s Atomic Model (1911)

Describes the atom as having a small, dense, positively charged nucleus where electrons orbit around, with most of the atom's volume being empty space.

Gold foil experiment

An experiment conducted by Rutherford that revealed the existence of a compact, positively charged nucleus by bouncing alpha particles off a thin gold foil.

Bohr’s Atomic Model (1913)

Illustrates that electrons orbit the nucleus in fixed paths without losing energy, with specific energy levels and the ability to jump between orbits.

Quantum Mechanical Model (Schrödinger, 1926)

Describes electrons as existing in probabilistic regions called orbitals, rather than fixed paths, using wave functions to determine their behavior.

Heisenberg’s Uncertainty Principle

States that the exact position and momentum of an electron cannot be simultaneously known, emphasizing the probabilistic nature of the electron's position.

Rutherford

implemented protons as the nucleus of the atom

The cathod ray tube experiment

led to the discovery of the electron, demonstrating that cathode rays are composed of negatively charged particles.

In the quantum atomic model

electrons are treated as wave functions, existing in probability distributions around the nucleus rather than defined orbits.

In the gold foil experiment certain particles bounced or passed through the gold foil because…

the dense positive nucleus reflected them, or they didn’t colide with it