The Atomic Theory

Unit 2:  Atomic Theory

Chemistry I CP

Poll

Which of these models do you think most accurately depicts the structure of the atom?

Democritus

• Ancient Greek philosopher

• Matter is made of solid spheres he called "atomos".

JJ (Joseph John)Thomson

• cathode ray tube

• discovered the electron

• Plum Pudding Model (also called Blueberry Muffin Model or Chocolate Chip Cookie Model)

Ernest Rutherford

• Gold foil experiment

• discovered the positively charged nucleus

• said the atom is mostly empty space except for the tiny, positive nucleus

• Planetary Model (also called the Rutherford-Bohr Model)

Neils Bohr

• used hydrogen to discover energy levels

• said that electrons travel around the nucleus in SPECIFIC "orbits" that he called energy levels like the planets orbit the sun

• Planetary Model (also called Rutherford-Bohr Model)

Richard Feynman

• discovered the electron cloud

• said electrons are most likely to be found at specific distances from the nucleus in what he called and electron "cloud"

• energy levels are not two dimensional paths but are three dimensional shells

• Electron Cloud Model

Open Ended

Describe the Plum Pudding Model of the atom in terms of the presence or absence and location of protons, neutrons, electrons, and a nucleus.

Open Ended

Describe the Planetary Model of the atom in terms of the presence or absence and location of protons, neutrons, electrons, and a nucleus.

Open Ended

Describe the Electron Cloud Model of the atom in terms of the presence or absence and location of protons, neutrons, electrons, and a nucleus.

Multiple Choice

Which model is the Democritus model of the atom?

Multiple Choice

Which model is the Plum Pudding Model?

Multiple Choice

Which model is the Planetary Model?

Multiple Choice

Which model is the Electron Cloud Model?