History of Atomic Models

Who first proposed the idea of indivisible particles called atoms?

• Democritus

• John Dalton

• J.J. Thomson

• Ernest Rutherford

What did John Dalton propose about elements?

• Each element is composed of unique atoms

• Atoms are indivisible particles

• Atoms have a small, dense nucleus

• Atoms exist in probability clouds

Which experiment led to the discovery of the atomic nucleus?

• Gold foil experiment

• Plum pudding model

• Electron discovery

• Quantum mechanical model

What did Niels Bohr introduce in his atomic model?

• Quantized electron orbits

• Probability clouds

• Positively charged 'soup'

• Unique atoms for each element

What does the quantum mechanical model describe about electrons?

• Exist in probability clouds

• Fixed orbits

• Embedded in a positively charged 'soup'

• Small, dense nucleus