Early Theories
Key Scientists
Atomic Models
Experiments
100

Who was the first person to use the term "atom," meaning indivisible? 

Democritus 

100

Who discovered the electron using cathode ray tube experiment? 

JJ Thomson (figured out the electrons) 

100

Neil Bohr's model proposed the atom: 

Electrons orbit the nucleus in fixed energy levels. 

100

Who discovered the nucleus through the gold foil experiment? Some rays passed through, while others reflected at different angles. 

Rutherford 

200

Which philosopher believed matter was made up of earth, air, fire, and water?

Aristotle 

200

JJ Thomson proposed which model of the atom? (Today we use the chocolate chip cookie dough example, but what was the original analogy) 

Plum Pudding Model 

200

The modern model of the atom is called: 

The Quantum Mechanical Model (electrons are in a cloud like region with different energy levels around the nucleus) 

200

Which experiment helped discover the electron? 

The Cathode Experiment 

300

What was the main conclusion from Rutherford's experiment? (Gold foil) 

Atoms have a dense, positively charged nucleus 

300

Who discovered the neutron, which has a neutral or no charge? 

James Chadwick 

300

Schrodinger & Heisenberg developed the most accepted and current model of an atom to date, which is called: 

A cloud like model. 

300

Which experiment measured the CHARGE of the electron? This was done by Milikan

The oil drop 

400

Which scientist is associated with the uncertainty principle? 

Heisenberg 

400

Who measured the electrons charge with the oil drop experiment?

Millikan 

400
The planetary model of electrons was proposed by which scientist? 

Neil Bohr 

400

Which scientist suggest electrons behave like waves?

Louis

500

Describe Dalton's contribution to atomic theory

  1. All matter is made of atoms. Atoms are indivisible and indestructible.

  2. All atoms of a given element are identical in mass and properties.

  3. Compounds are formed by a combination of two or more different kinds of atoms.

  4. A chemical reaction is a rearrangement of atoms.


500
The following scientist are arranged in what order of the discovery and experimenting of the atom:

Democritus, Dalton, Thomson, Rutherford, Bohr, Quantum Model 

Earliest to current 

500

Which atomic model was FIRST to include a dense nucleus 

Rutherford's Nuclear Model (gold foil) 

500

How did Bohr's model differ from Rutherford's model? 

Bohr's model focused that electrons orbited the nucleus in a given pattern.