11/30 - Notes: Atomic Theory

is considered to be the father of modern atomic thought.

Democritus proposed that matter is made of small, indivisible objects called .

proposed the first atomic theory that was based on experimentation.

found negative particles that were smaller than an atom, which he called .

Thomson’s atomic model stated that an atom is made of positively charged “dough” with negative electrons scattered throughout it.

Rutherford’s model was improved when proposed that electrons move in circular orbits, or around the nucleus.

discovered the a neutral particle in the nucleus of an atom.

In modern atomic theory, electrons are found in an , a hazy area around the nucleus in which an electron is likely to be located.