Untitled Flashcards Set

John Dalton's atomic theory (1805)

Proposed that atoms are indivisible, have solid sphere model, and that all atoms of an element are identical.

Thompson’s Plum Pudding Model

JJ Thompson's model from the late 1800s that depicted electrons as 'plums' in a positively charged 'pudding', but did not account for protons.

Millikan’s Oil Drop Experiment

Conducted by Robert Millikan in 1909, it discovered the charge of an electron, confirming that electrons are negatively charged.

Rutherford’s Gold Foil Experiment (1911)

Demonstrated the existence of the nucleus and protons, revealing that atoms consist mostly of empty space.

James Chadwick's discovery (1932)

Identified neutrons in the nucleus to account for unaccounted mass that had no charge.

Bohr's Atomic Model

Presented the idea of electron shells but failed to explain why electrons were in rigid shells.

Quantum Model of the atom

Posits that electrons are not in fixed shells but exist in certain regions of space as 'clouds'.